Part 45

HYDRANT, h[=i]'drant, _n._ a machine for discharging water: a water-plug. [Gr. _hyd[=o]r_, water.]

HYDRATE, h[=i]'dr[=a]t, _n._ a compound formed by the union of water with an oxide.--_n._ HYDR[=A]'TION. [Gr. _hyd[=o]r_, water.]

HYDRAULIC, -AL, h[=i]-drawl'ik, -al, _adj._ relating to hydraulics: conveying water: worked by water.--_adv._ HYDRAUL'ICALLY.--_n.pl._ HYDRAUL'ICS, used as _sing._, the science of hydrodynamics in its practical application to water-pipes, &c.--HYDRAULIC BELT, an arrangement for lifting water, consisting of an endless belt fitted with buckets which discharge as they turn over an upper wheel; HYDRAULIC CEMENT, lime, a cement that sets or hardens under water; HYDRAULIC JACK, a jack or lifting apparatus, by means of oil, &c., pressed by a force-pump against a piston or plunger; HYDRAULIC MINING, a method of mining by which the auriferous detritus is washed down by a powerful jet of water into a sluice where the gold is easily separated; HYDRAULIC PRESS, a press operated by the differential pressure of water on pistons of different dimensions; HYDRAULIC RAM, an automatic pump worked by the pressure of a column of water in a pipe, and the force acquired by intermittent motion of the column. [From Gr. _hyd[=o]r_, water, _aulos_, a pipe.]

HYDRIA, h[=i]'dri-a, _n._ a large Greek water-vase.--_n._ HY'DRIAD, a water-nymph.

HYDRID, h[=i]'drid, _n._ (_chem._) a substance consisting of hydrogen combined with an element or some compound radical.--_n._ HY'DRIODATE, a salt of hydriodic acid.--_adj._ HYDRIOD'IC, produced by the combination of hydrogen and iodine.

HYDROBAROMETER, h[=i]-dro-ba-rom'e-ter, _n._ an instrument for determining the depth of the sea by the pressure of the superincumbent water.

HYDROBROMIC, h[=i]-dro-br[=o]'mik, _adj._ compounded of bromine and hydrogen.--_n._ HYDROBR[=O]'MATE, a salt of hydrobromic acid--same as _bromide_; also _Bromhydrate_.

HYDROCARBON, h[=i]-dro-k[:a]r'bon, _n._ a compound of hydrogen and carbon.--HYDROCARBON FURNACE, a furnace in which liquid fuel, as petroleum, is used.

HYDROCELE, h[=i]'dro-s[=e]l, _n._ (_med._) a swelling consisting of a collection of serous fluid in the scrotum or in some of the coverings of the testicle or spermatic cord. [Gr. _hyd[=o]r_, water, _k[=e]l[=e]_, a swelling.]

HYDROCEPHALUS, h[=i]-dro-sef'a-lus, _n._ an accumulation of serous fluid within the cranial cavity, either in the sub-dural space or the ventricles: water in the head: dropsy of the brain.--_adjs._ HYDROCEPHAL'IC, HYDROCEPH'ALOID, HYDROCEPH'ALOUS. [Gr. _hyd[=o]r_, water, _kephal[=e]_, the head.]

HYDROCHLORIC, h[=i]-dro-kl[=o]'rik, _adj._ compounded of hydrogen and chlorine.--_n._ HYDROCHL[=O]'RATE, a salt of hydrochloric acid.

HYDROCYANIC, h[=i]-dro-s[=i]-an'ik, _adj._ noting an acid formed by the combination of hydrogen and cyanogen--also _Prussic acid_.--_ns._ HYDROCY'ANIDE, HYDROCY'ANITE.

HYDRODYNAMICS, h[=i]-dro-di-nam'iks, _n.pl._ used as _sing._, the science that treats of the motions and equilibrium of a material system partly or wholly fluid, called _Hydrostatics_ when the system is in equilibrium, _Hydrokinetics_ when it is not.--_adjs._ HYDRODYNAM'IC, -AL.--_n._ HYDRODYNAMOM'ETER, an instrument for measuring the velocity of fluid in motion by its pressure.--_adj._ HYDROELEC'TRIC, pertaining to electricity generated by the escape of steam under high pressure.--_n._ HY'DRO-EXTRACT'OR, an apparatus for removing moisture from yarns, cloths, &c., in process of manufacture. [Gr. _hyd[=o]r_, water, and _dynamics_.]

HYDROFLUORIC, h[=i]-dro-fl[=oo]-or'ik, _adj._ consisting of fluorine and hydrogen.

HYDROGEN, h[=i]'dro-jen, _n._ a gas which in combination with oxygen produces water, an elementary gaseous substance, the lightest of all known substances, and very inflammable.--_adjs._ HY'DRIC, containing hydrogen; HYDROG'ENOUS, containing hydrogen: produced by the action of water, as applied to rocks in opposition to those that are _pyrogenous_, formed by the action of fire. [A word coined by Cavendish (1766) from Gr. _hyd[=o]r_, water, and _gen[=e]s_, producing.]

HYDROGRAPHY, h[=i]-drog'ra-fi, _n._ the art of measuring and describing the size and position of waters or seas: the art of making sea-charts.--_n._ HYDROG'RAPHER, a maker of sea-charts.--_adjs._ HYDROGRAPH'IC, -AL.--_adv._ HYDROGRAPH'ICALLY. [Gr. _hyd[=o]r_, water, _graphein_, to write.]

HYDROKINETICS, h[=i]-dro-ki-net'iks, _n.pl._ used as _sing._, a branch of _Hydrodynamics_ (q.v.).

HYDROLOGY, h[=i]-drol'o-ji, _n._ the science which treats of water.--_adjs._ HYDROLOG'IC, -AL.--_n._ HYDROL'OGIST. [Gr. _hyd[=o]r_, water, _logia_, a discourse.]

HYDROLYSIS, h[=i]-drol'i-sis, _n._ a kind of chemical decomposition by which a compound is resolved into other compounds by taking up the elements of water.--_adj._ HYDROLYT'IC. [Gr. _hyd[=o]r_, water, _lysis_--_lyein_, to loose.]

HYDROMANCY, h[=i]'dro-man-si, _n._ divination by water.--_adj._ HYDROMANT'IC. [Gr. _hyd[=o]r_, water, _manteia_, divination.]

HYDROMANIA, h[=i]-dro-m[=a]'ni-a, _n._ an insatiable craving for water, as in diabetes: a morbid propensity to suicide by drowning.

HYDROMECHANICS, h[=i]-dro-me-kan'iks, _n._ the mechanics of fluids.

HYDROMEL, h[=i]'dro-mel, _n._ a beverage made of honey and water. [Gr. _hyd[=o]r_, water, _meli_, honey.]

HYDROMETAMORPHISM, h[=i]-dro-met-a-mor'fizm, _n._ a kind of metamorphism of igneous rocks brought about by water, in opposition to _Pyrometamorphism_, that brought about by means of heat.

HYDROMETEOROLOGY, h[=i]-dro-m[=e]-te-or-ol'o-ji, _n._ the branch of meteorology which treats of water in the atmosphere, as rain, clouds, snow, &c.--_n._ HYDROM[=E]'TEOR, any one of the aqueous phenomena of the atmosphere. [Gr. _hyd[=o]r_, water, _mete[=o]ron_, a meteor.]

HYDROMETER, h[=i]-drom'et-[.e]r, _n._ an instrument for measuring the density or specific gravity of solids and liquids by flotation, consisting of a weighted glass bulb or hollow metal cylinder with a long stem: a current-gauge.--_adjs._ HYDROMET'RIC, -AL.--_n._ HYDROM'ETRY. [Gr. _hyd[=o]r_, water, _metron_, a measure.]

HYDROMOTOR, h[=i]-dro-m[=o]'tor, _n._ a form of motor for propelling vessels by means of jets of water ejected from the sides or stern.

HYDROMYS, h[=i]'dro-mis, _n._ an Australasian genus of rodents, known as water-rats and beaver-rats. [Gr. _hyd[=o]r_, water, _mys_, mouse.]

HYDRONETTE, h[=i]'dro-net, _n._ a syringe: a garden force-pump.

HYDROPATHY, h[=i]-drop'a-thi, _n._ the treatment of disease by cold water.--_adjs._ HYDROPATH'IC, -AL.--_adv._ HYDROPATH'ICALLY.--_n._ HYDROP'ATHIST, one who practises hydropathy.--HYDROPATHIC ESTABLISHMENT or (_coll._) simply HYDROPATH'IC, a temperance hotel where the guests can have hydropathic treatment if desired. [Gr. _hyd[=o]r_, water, _pathos_, suffering, _pathein_, to suffer.]

HYDROPHANE, h[=i]'dro-f[=a]n, _n._ a partly translucent variety of opal which becomes transparent when wetted.--_adj._ HYDROPH'ANOUS. [Gr. HYD[=O]R, water, _phainein_, to shine.]

HYDROPHIDAE, h[=i]-drof'i-d[=e], _n.pl._ a family of venomous sea-snakes. [Gr. _hyd[=o]r_, water, _ophis_, snake.]

HYDROPHOBIA, h[=i]-dro-f[=o]'bi-a, _n._ an unnatural dread of water, a symptom of a disease known as Rabies, usually resulting from the bite of a mad dog--hence the disease itself.--_adj._ HYDROPHOB'IC. [Gr. _hyd[=o]r_, water, _phobos_, fear.]

HYDROPHONE, h[=i]'dro-f[=o]n, _n._ a marine electric apparatus for detecting the approach of a torpedo-boat, &c.

HYDROPHORE, h[=i]'dro-f[=o]r, _n._ an apparatus for obtaining specimens of water from any required depth.

HYDROPHTHALMIA, h[=i]-drof-thal'mi-a, _n._ an increase in quantity of the aqueous or the vitreous humour.

HYDROPHYTE, h[=i]'dro-f[=i]t, _n._ a plant living in water.--_n._ HYDROPHYTOG'RAPHY, the branch of botany which describes such--also HYDROPHYTOL'OGY. [Gr. _hyd[=o]r_, water, _phyton_, a plant, _logia_, discourse.]

HYDROPSY, h[=i]'drop-si, _n._ dropsy.--_adjs._ HYDROP'IC, HYDROP'TIC, dropsical: thirsty.

HYDROPULT, h[=i]'dro-pult, _n._ a hand force-pump.

HYDROSAURUS, h[=i]-dro-saw'rus, _n._ a genus of monitor-lizards, of aquatic habit, found in the Malay Peninsula, &c. [Gr. _hyd[=o]r_, water, _sauros_, a lizard.]

HYDROSCOPE, h[=i]'dro-sk[=o]p, _n._ a kind of water-clock, consisting of a cylindrical graduated tube, from which the water escaped through a hole in the bottom. [Gr. _hyd[=o]r_, water, _skopein_, to view.]

HYDROSOMA, h[=i]-dro-s[=o]'ma, _n._ the entire organism of any hydrozoon:--_pl._ HYDROS[=O]'MATA.--_adjs._ HYDROS[=O]'MAL, HYDROS[=O]'MATOUS.

HYDROSTATICS, h[=i]-dro-stat'iks, _n.pl._ used as _sing._, a branch of HYDRODYNAMICS (which see).--_n._ HY'DROSTAT, an electrical contrivance for detecting a leakage or overflow of water: an apparatus devised to guard against the explosion of steam boilers.--_adjs._ HYDROSTAT'IC, -AL.--_adv._ HYDROSTAT'ICALLY.--HYDROSTATIC BALANCE, a balance for weighing bodies in water to determine their specific gravity; HYDROSTATIC BELLOWS, a device for illustrating the law that fluid pressure is proportional to area; HYDROSTATIC PARADOX, the principle that (disregarding molecular forces) any quantity of fluid, however small, may balance any weight, however great, as in the hydrostatic bellows; HYDROSTATIC PRESS, the same as Hydraulic Press.

HYDROSULPHURIC, h[=i]-dro-sul-f[=u]'rik, _adj._ formed by a combination of hydrogen and sulphur.

HYDROTELLURIC, h[=i]-dro-tel-l[=u]'rik, _adj._ pertaining to hydrogen and tellurium.

HYDRO-THERAPEUTICS, h[=i]-dro-ther-a-p[=u]'tiks, _n.pl._ remedial treatment of disease by water in various modes and forms--also HYDROTHER'APY.--_adj._ HYDROTHERAPEU'TIC.

HYDROTHERMAL, h[=i]-dro-ther'mal, _adj._ pertaining to, or produced by,

## action of heated or super-heated water, esp. in dissolving, transporting,

and redepositing mineral matter.

HYDROTHORAX, h[=i]-dro-th[=o]'raks, _n._ a term applied to dropsical collections in the pleura. [Gr. _hyd[=o]r_, water, _th[=o]rax_, chest.]

HYDROTROPISM, h[=i]-dro-trop'izm, _n._ the habit induced in a growing organ by the influence of moisture, of turning toward, or away from, the moisture.--_adj._ HYDROTROP'IC. [Gr. _hyd[=o]r_, water, _tropos_, a turn.]

HYDROUS, h[=i]'drus, _adj._ watery, containing hydrogen.

HYDROXIDE, h[=i]-droks'[=i]d, _n._ a metallic or basic radical combined with one or more hydroxyl groups.--_n._ HYDROX'YL, a compound radical not yet isolated, but found in many chemical compounds.

HYDROZOA, h[=i]-dro-z[=o]'a, _n.pl._ (_sing._ HYDROZ[=O]'ON) one of the main divisions of the sub-kingdom _Coelenterata_, the other two being _Ctenophora_ and _Anthozoa_ or _Actinozoa_; they are chiefly marine organisms, soft and gelatinous, free or fixed, existing everywhere, endlessly varied in form and complexity of structure, including such great groups as _hydroids_, _acalephs_, _medusans_, jelly-fish, sea-blubbers, &c.--_adjs._ HYDROZ[=O]'AN, HYDROZ[=O]'IC. [Gr. _hyd[=o]r_, water, _z[=o]on_, an animal.]

HYDRURET. Same as HYDRID.

HYENA, h[=i]-[=e]'na, HYEN, h[=i]'en, _n._ (_Shak._) a hyaena.

HYETAL, h[=i]'e-tal, _adj._ rainy.--_n._ HY'ETOGRAPH, a chart showing the average rainfall of the earth or any of its divisions.--_adjs._ HYETOGRAPH'IC, -AL.--_ns._ HYETOG'RAPHY; HYETOL'OGY; HYETOM'ETER; HYETOMET'ROGRAPH. [Gr. _hyetos_, rain.]

HYGEIAN, h[=i]-j[=e]'an, _adj._ relating to health and its preservation.--_ns._ HYGEIA (h[=i]-j[=e]'a), goddess of health, daughter of Aesculapius; HY'GI[=E]NE, HYGIEN'ICS, HY'GIENISM, the science which treats of the preservation of health.--_adj._ HYGIEN'IC.--_adv._ HYGIEN'ICALLY.--_n._ HY'GIENIST, one skilled in hygiene; HYGIOL'OGY, art of the preservation of health. [Gr. _hygieia_--_hygi[=e]s_, healthy.]

HYGRODEIK, h[=i]'gro-d[=i]k, _n._ a form of hygrometer in which the atmospheric humidity is indicated by an index controlled by the heights of a wet-bulb and a dry-bulb thermometer, supported on each side of a frame on which is described a scale. [Gr. _hygros_, wet, _deik-nynai_, to show.]

HYGROMETER, h[=i]-grom'et-[.e]r, _n._ an instrument for measuring the moisture in the atmosphere, or its relative humidity.--_n._ HYGROM'ETRY, the art of measuring the moisture in the atmosphere, and of bodies generally.--_adjs._ HYGROMET'RIC, -AL. [Gr. _hygros_, wet, _metron_, a measure.]

HYGROSCOPE, h[=i]'gro-sk[=o]p, _n._ an instrument for indicating the humidity of the atmosphere.--_adjs._ HYGROSCOP'IC, -AL.--_ns._ HYGROSCOPIC'ITY; HYGROSTAT'ICS, the art of measuring degrees of moisture. [Gr. _hygros_, wet, _skopein_, to view.]

HYKSOS, hik'sos, _n._ the shepherd kings, apparently a Tartar race who overthrew the reigning dynasty of Lower Egypt about 2000 B.C., and reigned until overturned by the Egyptian rulers of Upper Egypt about 1700 B.C.

HYLEG, h[=i]'leg, _n._ the planet which rules at the hour of one's birth, in that sign of the zodiac immediately above the eastern horizon. [Ar.]

HYLISM, h[=i]'lizm, _n._ materialism--also HY'LICISM.--_ns._ HY'LICIST; HYLOGEN'ESIS, the origin of matter; HY'LOTHEISM, the doctrine that there is no God but matter and the universe.--_adjs._ HYLOZ[=O]'ICAL, HYLOZOIS'TIC.--_ns._ HYLOZ[=O]'ISM, the doctrine that all matter is endowed with life; HYLOZ[=O]'IST.

HYLOPATHISM, h[=i]-lop'a-thizm, _n._ the doctrine that matter is sentient.--_n._ HYLOP'ATHIST, one who maintains this. [Gr. _hyl[=e]_, matter, _pathos_, suffering.]

HYMEN, h[=i]'men, _n._ (_myth._) the god of marriage: marriage: a thin membrane partially closing the virginal vagina.--_adjs._ HYMEN[=E]'AL, HYMEN[=E]'AN.--_n._ HYM[=E]'NIUM, the fructifying surface in fungi. [L.,--Gr. _hym[=e]n_; cf. Gr. _hymnos_, a festive song.]

HYMENOPTERAL, h[=i]-men-op't[.e]r-al, _adj._ pertaining to the HYMENOP'TERA, an order of insects having four membranous wings.--Also HYMENOP'TEROUS. [Gr. _hym[=e]n_, a membrane, _pteron_, a wing.]

HYMENOTOMY, h[=i]-men-ot'o-mi, _n._ the cutting or dissection of membranes.

HYMN, him, _n._ a song of praise, a metrical formula of public worship.--_v.t._ to celebrate in song: to worship by hymns.--_v.i._ to sing in adoration.--_ns._ HYM'NAL, HYM'NARY, a hymn-book.--_adj._ HYM'NIC, relating to hymns.--_ns._ HYM'NODY, hymns collectively: hymnology; HYMNOG'RAPHER; HYMNOG'RAPHY, the art of writing hymns; HYMNOL'OGIST; HYMNOL'OGY, the study or composition of hymns. [Gr. _hymnos_.]

HYOID, h[=i]'oid, _adj._ having the form of the Greek letter upsilon ([Greek: u]), applied to a bone at the base of the tongue. [Gr. _hyoeid[=e]s_--the letter [Greek: u], and _eidos_, form.]

HYOSCYAMINE, h[=i]-[=o]-sk[=i]'a-m[=i]n, _n._ a very poisonous alkaloid found in the seeds of _Hyoscyamus niger_, or henbane. [Gr. _hyoskyamos_, henbane.]

HYP. See HIP (3).

HYPAETHRAL, hip-[=e]'thral, _adj._ roofless, open to the sky.--_n._ HYPAE'THRON, an open court. [Gr. _hypo_, beneath, _aith[=e]r_, air.]

HYPALGESIA, hip-al-j[=e]'si-a, _n._ diminished susceptibility to painful impressions--also HYPERAL'GIA.--_adj._ HYPERALG[=E]'SIC. [Gr. _hypo_, under, _algos_, pain.]

HYPALLAGE, hi-pal'a-j[=e], _n._ (_rhet._) a figure in which the relations of things in a sentence are mutually interchanged, but without obscuring the sense. [Fr.,--L.,--Gr. _hypallassein_, to interchange--_hypo_, under, _alassein_, to change.]

HYPERACUTE, h[=i]-per-a-k[=u]t', _adj._ excessively acute.--_n._ HYPERACUTE'NESS.

HYPERAESTHESIA, h[=i]-per-es-th[=e]'si-a, _n._ (_path._) excessive sensibility.--_adj._ HYPERAESTHET'IC.

HYPERBATON, h[=i]-per'ba-ton, _n._ (_rhet._) a figure by which words are transposed from their natural order.--_adj._ HYPERBAT'IC.--_adv._ HYPERBAT'ICALLY. [Gr.,--_hyperbainein_--_hyper_, beyond, _bainein_, to go.]

HYPERBOLA, h[=i]-per'bo-la, _n._ (_geom._) one of the conic sections or curves formed when the intersecting plane makes a greater angle with the base than the side of the cone makes.--_adjs._ HYPERBOL'IC, -AL.--_adv._ HYPERBOL'ICALLY.--_adjs._ HYPERBOL'IFORM; HYPER'BOLOID. [L.,--Gr. _hyperbol[=e]_, from _hyperballein_--_hyper_, beyond, _ballein_, to throw.]

HYPERBOLE, h[=i]-per'bo-le, _n._ a rhetorical figure which produces a vivid impression by representing things as much greater or less than they really are--not expecting to be taken literally: an obvious exaggeration.--_adjs._ HYPERBOL'IC, -AL.--_adv._ HYPERBOL'ICALLY.--_v.t._ HYPER'BOLISE, to represent hyperbolically.--_v.i._ to speak hyperbolically or with exaggeration.--_n._ HYPER'BOLISM. [A doublet of the above.]

HYPERBOREAN, h[=i]-per-b[=o]'r[=e]-an, _adj._ belonging to the extreme north.--_n._ an inhabitant of the extreme north. [Gr. _hyperboreos_--_hyper_, beyond, _Boreas_, the north wind.]

HYPERCATALECTIC, h[=i]-per-kat-a-lek'tik, _adj._ (_pros._) having an additional syllable or half-foot after the last complete dipody.--_n._ HYPERCATALEX'IS.

HYPERCRITIC, h[=i]-per-krit'ik, _n._ one who is over-critical.--_adjs._ HYPERCRIT'IC, -AL, over-critical.--_adv._ HYPERCRIT'ICALLY.--_v.t._ HYPERCRIT'ICISE, to criticise with too much nicety.--_n._ HYPERCRIT'ICISM.

HYPERDULIA, h[=i]-per-d[=u]-l[=i]'a, _n._ the special kind of worship paid by Roman Catholics to the Virgin Mary, being higher than that paid to other saints (_dulia_), and distinct from that paid to God alone (_latria_). [Gr. _hyper_, beyond, _douleia_, service.]

HYPEREMESIS, h[=i]-per-em'e-sis, _n._ excessive vomiting.--_adj._ HYPEREMET'IC. [Gr. _hyper_, over, _emesis_, vomiting.]

HYPEREMIA, HYPERAEMIA, h[=i]-per-[=e]'mi-a, _n._ an excessive accumulation of blood in any part of the body.--_adjs._ HYPEREM'IC, HYPERAE'MIC. [Gr. _hyper_, over, _haima_, blood.]

HYPERESTHETIC, h[=i]-per-es-thet'ik, _adj._ morbidly sensitive.--Also HYPERESTH[=E]'SIC.

HYPERICUM, h[=i]-per'i-kum, _n._ a large genus of plants, of which St John's wort is a typical species. [Gr. _hypo_, under, _ereik[=e]_, heath.]

HYPERINOSIS, h[=i]-per-i-n[=o]'sis, _n._ excess of fibrin in the blood:--_opp._ to HYPINOSIS.--_adj._ HYPERINOT'IC.

HYPERION, h[=i]-p[=e]r'i-on, _n._ a Titan, son of Uranus and Ge, and father of Helios, Selene, and Eos: Helios himself, the incarnation of light and beauty.

HYPERMETRICAL, h[=i]-per-met'rik-al, _adj._ beyond or exceeding the ordinary metre of a line: having a syllable too much.--_n._ HYPER'METER.

HYPERMETROPIA, h[=i]-per-me-tr[=o]'pi-a, _n._ long-sightedness, the opposite of _Myopia_---also HYPEROP'IA.--_adj._ HYPERMETROP'IC. [Gr. _hyper_, beyond, _metron_, measure, _[=o]ps_, eye.]

HYPERORTHODOX, h[=i]-per-or'th[=o]-doks, _adj._ extremely orthodox--_n._ HYPEROR'THODOXY.

HYPERPHASIA, h[=i]-per-f[=a]'zi-a, _n._ (_path._) lack of control of the organs of speech.--_adj._ HYPERPH[=A]'SIC.

HYPERPHYSICAL, h[=i]-per-fiz'ik-al, _adj._ beyond physical laws: supernatural.

HYPERPLASIA, h[=i]-per-pl[=a]'si-a, _n._ (_path._) overgrowth of a part due to excessive multiplication of its cells.--_adjs._ HYPERPLAS'IC, HYPERPLAS'TIC. [Gr. _hyper_, over, _plasis_, a forming--_plassein_, to form.]

HYPERSARCOSIS, h[=i]-per-sar-k[=o]'sis, _n._ (_path._) proud or fungous flesh.--Also HYPERSARC[=O]'MA.

HYPERSENSITIVE, h[=i]-per-sen'si-tiv, _adj._ excessively sensitive.--_n._ HYPERSEN'SITIVENESS.

HYPERSTHENE, h[=i]-per-sth[=e]n', _n._ a rock-forming mineral which crystallises in orthorhombic forms, an anhydrous magnesian silicate, generally dark green or raven-black in colour.--_adj._ HYPERSTH[=E]'NIC.--_n._ HYPERSTH[=E]'NITE, a more or less coarsely crystalline igneous rock, allied to gabbro--an aggregate of labradorite (feldspar) and hypersthene, of plutonic origin. [Gr. _hyper_; above, _sthenos_, strength.]

HYPERSTHENIA, h[=i]-per-sth[=e]'ni-a, _n._ (_path._) a morbid condition marked by excessive excitement of all the vital phenomena.--_adj._ HYPERSTH[=E]'NIC. [Gr. _hyper_, above, _sthenos_, strength.]

HYPERTHESIS, h[=i]-per'the-sis, _n._ a transfer of a letter from its own to the syllable immediately before or after.--_adj._ HYPERTHET'IC. [Gr. _hyper_, over, _thesis_--_tithenai_, to put.]

HYPERTROPHY, h[=i]-per'tro-fi, _n._ over-nourishment: the state of an organ or part of the body when it grows too large from over-nourishment.--_adjs._ HYPERTROPH'IC, -AL, HYPER'TROPHIED, HYPER'TROPHOUS. [Gr. _hyper_, above, _troph[=e]_, nourishment.]

HYPHEN, h[=i]'fen, _n._ a short stroke (-) joining two syllables or words.--_adj._ HYPHEN'IC. [Gr. _hypo_, under, _hen_, one.]

HYPNOTISM, hip'no-tizm, _n._ a sleep-like condition induced by artificial means: a nervous sleep like the condition under mesmerism.--_n._ HYPNOGEN'ESIS, production of hypnotism--also HYPNOG'ENY.--_adj._ HYPNOGENET'IC.--_adv._ HYPNOGENET'ICALLY.--_adjs._ HYPNOGEN'IC, HYPNOT'IC, having the property of producing sleep; HYPNOG'ENOUS.--_ns._ HYPNOL'OGY, the sum of knowledge about sleep; HYPN[=O]'SIS, the production of sleep: the hypnotic state; HYPNOT'IC, a medicine that induces sleep; HYPNOTISABIL'ITY.--_adj._ HYP'NOTISABLE.--_n._ HYPNOTIS[=A]'TION.--_v.t._ HYP'NOT[=I]SE, to subject to hypnotism, to produce hypnotic sleep in any one.--_n._ HYP'NOT[=I]SER.--_adjs._ HYPNOTIS'TIC; HYP'NOTOID, like hypnotism. [Coined in 1843 from Gr. _hypnos_, sleep.]

HYPNUM, hip'num, _n._ the largest genus of mosses, order _Bryineae_, having archegonia and capsules borne on special lateral branches.

HYPOBOLE, hip-pob'o-l[=e], _n._ (_rhet._) the mention in argument of things apparently damaging to one's side, with the successive refutation of each. [Gr.]

HYPOCAUST, hip'o-kawst, _n._ among the ancients, a vaulted chamber from which the heat of stoves was distributed to baths or rooms above: now applied to the fireplace of a stove or hothouse. [Gr. _hypokauston_--_hypo_, under, _kaiein_, to burn.]

HYPOCHONDRIA, hip-o-kon'dri-a, _n._ a nervous malady, often arising from indigestion, and tormenting the patient with imaginary fears--more correctly, HYPOCHONDR[=I]'ASIS--also HYPOCHONR[=I]'ACISM, HYPOCHONDR[=I]'ASIS, HYPOCHON'DRIASM.--_n._ HYPOCHON'DRIAC, one suffering from hypochondria--also HYPOCHON'DRIAST.--_adjs._ HYPOCHON'DRIAC, -AL, relating to or affected with hypochondria: melancholy.--_n._ HYPOCHON'DRIUM (_anat._), that region of the abdomen situated on either side, under the costal cartilages and short ribs. [L.,--Gr., from _hypo_, under, _chrondos_, a cartilage.]

HYPOCIST, h[=i]'po-sist, _n._ an inspissated juice from a parasitic plant of the cytinus family.

HYPOCRISY, hi-pok'ri-si, _n._ a feigning to be what one is not: concealment of true character. [Gr. _hypokrisis_--_hypokrinesthai_, to play on the stage, from _hypo_, under, _krinein_, to decide.]

HYPOCRITE, hip'o-krit, _n._ one who practises hypocrisy.--_adj._ HYPOCRIT'ICAL, practising hypocrisy.--_adv._ HYPOCRIT'ICALLY. [Fr.,--L.,--Gr. _hypokrit[=e]s_.]

HYPOCYCLOID, h[=i]-po-s[=i]'kloid, _n._ a curve generated by a point on the circumference of a circle which rolls on the inside of another circle.--_adj._ HYPOCYOLOID'AL.

HYPODERMIC, h[=i]-po-der'mik, _adj._ relating to the parts under the skin, subcutaneous, esp. of a method of injecting a drug in solution under the skin by means of a fine hollow needle to which a small syringe is attached--also HYPODER'MAL.--_n._ HYPODER'MA, the layer of colourless cells immediately beneath the epidermis of a leaf. [Gr. _hypo_, under, _derma_, the skin.]

HYPOGASTRIC, hip-o-gas'trik, _adj._ belonging to the lower part of the abdomen.--_ns._ HYPOGAS'TRIUM, the lower part of the belly; HYPOGAS'TROCELE, a hernia through the walls of the lower belly. [Gr. _hypo_, under, _gast[=e]r_, the belly.]

HYPOGENE, h[=i]'po-j[=e]n, _adj._ (_geol._) of or pertaining to rocks which have assumed their present structure under the surface, plutonic:--opp. to _Epigene_.--_adj._ HYPOG'ENOUS (_bot._), produced below the surface, of fungi growing on the under side of leaves:--opp. to _Epigenous_ and _Epiphyllous_. [Gr. _hypo_, under, _gen[=e]s_, produced.]

HYPOGEUM, h[=i]-po-j[=e]'um, _n._ the part of a building below the ground, any underground chamber.--_adjs._ HYPOG[=E]'AL, HYPOGAE'AN, HYPOG[=E]'AN, subterranean. [Gr. _hypo_, under, _g[=e]_, the ground.]

HYPOGLOSSAL, h[=i]-po-glos'al, _adj._ situated under the tongue. [Gr. _hypo_, under, _gl[=o]ssa_, the tongue.]

HYPOGNATHOUS, h[=i]-pog'n[=a]-thus, _adj._ (_ornith._) having the under mandible longer than the upper, as the black skimmer.--_n._ HYPOG'NATHISM.

HYPOGYNOUS, h[=i]-poj'i-nus, _adj._ (_bot._) growing from beneath the ovary, said of certain parts of plants. [Gr. _hypo_, under, _gyn[=e]_, a woman.]

HYPONASTY, h[=i]'po-nas-ti, _n._ (_bot._) increased growth along the lower surface of an organ or part of a plant, causing the part to bend upward:--opp. to _Epinasty_.

HYPOPHOSPHITE, h[=i]-po-fos'f[=i]t, _n._ (_chem._) a salt obtained by the union of hypophosphorous acid with a salifiable base--also HYPOPHOS'PHATE.--_adjs._ HYPOPHOSPHOR'IC, HYPOPHOS'PHOROUS, containing less oxygen than phosphorous acid contains.

HYPOPHYSIS, h[=i]-pof'i-sis, _n._ the pituitary body of the brain: (_bot._) an inflated part of the pedicel under the capsule, in mosses; in flowering plants, a cell of the embryo producing the primary root and root-cap. [Gr. _hypo_, under, _phyein_, to grow.]

HYPOSTASIS, h[=i]-pos'ta-sis, _n._ a substance: the essence or real personal subsistence or substance of each of the three divisions of the Godhead.--_adjs._ HYPOSTAT'IC, -AL.--_adv._ HYPOSTAT'ICALLY.--_v.t._ HYPOS'TAT[=I]SE. [L.,--Gr. _hypostasis_--_hyphist[=e]mi_--_hypo_, under, _hist[=e]mi_, I make to stand.]

HYPOSTROPHE, h[=i]-pos'tro-fe, _n._ return of a disease, relapse: (_rhet._) use of insertion or parenthesis.

HYPOSTYLE, h[=i]'po-st[=i]l, _adj._ (_archit._) having the roof supported by pillars. [Gr. _hypo_, under, _stylos_, a pillar.]

HYPOSULPHUROUS, h[=i]-po-sul'fer-us, _adj._ next in a series below sulphurous.--Also HYPOSULPH[=U]'RIC.

HYPOTAXIS, h[=i]-po-tak'sis, _n._ (_gram._) dependent construction--opp. to _Parataxis_.--_adj._ HYPOTAC'TIC.

HYPOTENUSE, h[=i]-pot'en-[=u]s, or hip-, HYPOTHENUSE, h[=i]-poth'en-[=u]s, _n._ the side of a right-angled triangle opposite to the right angle. [Fr.,--Gr. _hypoteinousa_ (_gramm[=e]_), lit. (a line) 'which stretches under'--_hypo_, under, _teinein_, to stretch.]

HYPOTHEC, h[=i]-poth'ek, _n._ in Scotch law, a lien or security over goods in respect of a debt due by the owner of the goods.--ADJ. _Hypoth'ecary_, pertaining to hypothecation or mortgage.--_v.t._ HYPOTH'EC[=A]TE, to place or assign anything as security under an arrangement: to mortgage.--_ns._ HYPOTHEC[=A]'TION; HYPOTH'ECATOR. [Fr.,--L. _hypotheca_--Gr. _hypoth[=e]k[=e]_, a pledge.]

HYPOTHESIS, h[=i]-poth'e-sis, _n._ a supposition: a proposition assumed for the sake of argument: a theory to be proved or disproved by reference to facts: a provisional explanation of anything.--_v.i._ HYPOTH'ESIZE, to form hypotheses.--_adjs._ HYPOTHET'IC, -AL, belonging to a hypothesis: conditional.--_adv._ HYPOTHET'ICALLY. [Gr., _hypo_, under, _tithenai_, to place.]

HYPOTYPOSIS, h[=i]-po-ti-p[=o]'sis, _n._ (_rhet._) vivid description of a scene.

HYPOZOIC, h[=i]-po-z[=o]'ik, _adj._ (_geol._) below the limit of life: belonging to the HYPOZ[=O]'A.--_adj._ and _n._ HYPOZ[=O]'AN.

HYPSOMETRY, hip-som'e-tri, _n._ the art of measuring the heights of places on the earth's surface by means of the HYPSOM'ETER.--_adj._ HYPSOMET'RIC. [Gr. _hypsi_, on high, _metron_, a measure.]

HYPURAL, h[=i]-p[=u]'ral, _adj._ situated beneath the tail.

HYRAX, h[=i]'raks, _n._ a genus of mammals of obscure affinities, like rabbits in size and marmots in appearance, living among rocks in Africa and Syria--the _Cape Daman_, _Klippdass_, or _Rock-badger_; the _Shaphan_ (_Hyrax syriacus_) mistranslated 'cony' of Scripture; and the Abyssinian _Ashtok_.

HYSON, h[=i]'son, _n._ a very fine sort of green tea.--_n._ HY'SON-SKIN, the refuse of hyson tea. [Chinese.]

HYSSOP, his'up, _n._ an aromatic plant. [Fr.,--L. _hyssopum_--Gr. _hyss[=o]pos_--Heb. _[=e]z[=o]ph_.]

HYSTERANTHOUS, his-ter-an'thus, _adj._ (_bot._) having the leaves appearing after the flowers.

HYSTERESIS, his-te-r[=e]'sis, _n._ magnetic friction in dynamos, by which every reversal of magnetism in the iron causes dissipation of energy. [Gr. _hyster[=e]sis_, a deficiency--_hysteros_, later.]

HYSTERIC, -AL, his-ter'ik, -al, _adj._ pertaining to, of the nature of, or affected with hysterics or hysteria: like hysterics, fitfully and violently emotional.--_adv._ HYSTER'ICALLY.--_ns._ HYSTER'ICS, HYST[=E]R'IA, a nervous affection occurring typically in paroxysms of laughing and crying alternately, with a choking sensation in the throat, but often as a counterfeit of some organic disease.--_adjs._ HYS'TEROID, -AL, like hysteria.--_ns._ HYSTEROM[=A]N'IA, hysterical mania, often marked by erotic delusions and an excessive desire to attract attention; HYSTEROT'OMY, the operation of cutting into the uterus. [L. _hystericus_--Gr. _hysterikos_--_hystera_, the womb.]

HYSTERON-PROTERON, his'ter-on-prot'er-on, _n._ a figure of speech in which what should follow comes first: an inversion. [Gr., lit. 'the last first.']

HYTHE, h[=i]th, _n._ Same as HITHE.

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I the ninth letter in the alphabet of western Europe, called _iota_ by the Greeks, from its Semitic name _yod_, in most European languages the sound that of the Latin long _i_, which we have in the words _machine_ and _marine._ The normal sound of _i_ in English is that heard in _bit_, _dip_, _sit_, which is the short Latin _i_.

I, [=i], _pron._ the nominative case singular of the first personal pronoun: the word used by a speaker or writer in mentioning himself: the object of self-consciousness, the ego. [M. E. _ich_--A.S. _ic_; Ger. _ich_, Ice. _ek_, L. _ego_, Gr. _eg[=o]_, Sans. _aham_.]

I, [=i], _adv._ same as AY.--I', a form of _in_.

IAMBUS, [=i]-am'bus, _n._ a metrical foot of two syllables, the first short and the second long, as in L. _f[)i]d[=e]s_; or the first unaccented and the second accented, as in _deduce_--also IAMB'.--_adj._ IAM'BIC, consisting of iambics.--_n._ iambus.--_adv._ IAM'BICALLY, in the manner of an iambic.--_v.i._ IAM'BISE, to satirise in iambic verse.--_n._ IAMBOG'RAPHER, a writer of iambics. [L.,--Gr. _iambos_, from _iaptein_, to assail, this metre being first used by writers of satire.]

IANTHINA, [=i]-an-th[=i]'na, _n._ a genus of gregarious, pelagic gasteropods, having a snail-like shell, but delicate, translucent, and blue in colour. [Gr. _ianthinos_--_ion_, a violet, _anthos_, a flower.]

IATRIC, -AL, [=i]-at'rik, -al, _adj._ relating to medicine or physicians.--_adj._ IATROCHEM'ICAL, pertaining to IATROCHEM'ISTRY, a system of applying chemistry to medicine introduced by Francis de la Boe of Leyden (1614-72).--_n._ IATROL'OGY, a treatise on medicine.

IBERIAN, [=i]-b[=e]'ri-an, _adj._ Spanish.--_n._ one of the primitive inhabitants of Spain, of whom some think the Basques a remnant. [L. _Iberia_, Spain.]

IBEX, [=i]'beks, _n._ a genus of goats, inhabiting the Alps and other mountainous regions. [L.]

IBIDEM, ib-[=i]'dem, _adv._ in the same place. [L.]

IBIS, [=i]'bis, _n._ a genus of wading birds related to the stork, one species of which was worshipped by the ancient Egyptians. [L.,--Gr.; an Egyptian word.]

ICARIAN, [=i]-k[=a]'ri-an, _adj._ belonging to, or like, Icarus. [L. _Icarius_--Gr. _Ikarios_--_Ikaros_, who fell into the sea on his flight from Crete, his waxen wings being melted by the sun.]