ONICOLO, [=o]-nik'[=o]-l[=o], _n._ a variety of onyx for cameos, a bluish-white band on the dark ground. [It.]
ONION, un'yun, _n._ the name given to a few species of genus _Allium_, esp.
_Allium cepa_, an edible biennial bulbous root.--_adj._ ON'ION-EYED (_Shak._), having the eyes full of tears.--_n._ ON'ION-SKIN, a very thin variety of paper.--_adj._ ON'IONY. [Fr. _oignon_--L. _unio_, _-onis_--_unus_, one.]
ONLOOKER, on'l[=oo]k-[.e]r, _n._ a looker on, observer.--_adj._ ON'LOOKING.
ONLY, [=o]n'li, _adj._ single in number or kind: this above all others: alone.--_adv._ in one manner: for one purpose: singly: merely: barely: entirely.--_conj._ but: except that.--_n._ ON'LINESS. [A.S. _anlic_ (adj.)--_an_, one, _lic_, like.]
ONOCENTAUR, on-o-sen'tawr, _n._ a kind of centaur, half-man, half-ass.
ONOCLEA, on-[=o]-kl[=e]'a, _n._ a genus of aspidioid ferns, with contracted fertile fronds. [Gr. _onos_, a vessel, _kleiein_, to close.]
ONOLOGY, [=o]-nol'[=o]-ji, _n._ foolish talk.
ONOMANTIC, on-[=o]-man'tik, _adj._ pertaining to ON'OMANCY or (_obs._) ONOMAT'OMANCY, divination by names. [Gr. _onoma_, a name, _manteia_, divination.]
ONOMASTIC, on-[=o]-mas'tik, _adj._ pertaining to a name, esp. pertaining to the signature to a paper written in another hand.--_n._ ONOMAS'TICON, a list of words: a vocabulary. [Gr., from _onoma_, a name.]
ONOMATOLOGY, on-[=o]-ma-tol'o-ji, _n._ the science of, or a treatise on, the derivation of names.--_n._ ONOMATOL'OGIST, one versed in such. [Gr.
_onoma_, _onomatos_, name, _logia_--_legein_, to discourse.]
ONOMATOPOEIA, on-[=o]-mat-o-p[=e]'ya, _n._ the formation of a word so as to resemble the sound of the thing of which it is the name: such a word itself, also the use of such a word, as 'click,' 'cuckoo'--also ONOMATOPO[=E]'SIS, or ONOMATOPOI[=E]'SIS.--_adjs._ ONOMATOPOE'IC, ONOMATOPOET'IC. [Gr. _onoma_, _-atos_, a name, _poiein_, to make.]
ONSET, on'set, _n._ violent attack: assault: storming. [_On_ and _set_.]
ONSHORE, on'sh[=o]r, _adj._ toward the land.
ONSLAUGHT, on'slawt, _n._ an attack or onset: assault. [A.S. _on_, on, _sleaht_, a stroke.]
ONST, wunst, _adv._ a vulgar form of _once_.
ONSTEAD, on'sted, _n._ (_Scot._) a farmstead, the farm buildings. [M. E.
_wone_--A.S. _wunian_, to dwell, _stead_, place.]
ONTOGENESIS, on-t[=o]-jen'e-sis, _n._ the history of the individual development of an organised being as distinguished from _phylogenesis_ and _biogenesis_--also ONTOG'ENY.--_adjs._ ONTOGENET'IC, -AL, ONTOGEN'IC.--_adv._ ONTOGENET'ICALLY. [Gr. _onta_, things being, neut. pl.
of _[=o]n_, pr.p. of _einai_, to be, _genesis_, generation.]
ONTOLOGY, on-tol'o-ji, _n._ the science that treats of the principles of pure being: that part of metaphysics which treats of the nature and essence of things.--_adjs._ ONTOLOG'IC, -AL.--_adv._ ONTOLOG'ICALLY.--_n._ ONTOL'OGIST, one versed in ontology. [Gr. _[=o]n_, _ontos_, being pr.p. of _einai_, to be, _logia_--_legein_, to discourse.]
ONUS, [=o]'nus, _n._ burden: responsibility.--ONUS PROBAND[=I], the burden of proving. [L. _onus_, burden.]
ONWARD, on'ward, _adj._ going on: advancing: advanced.--_adv._ (also ON'WARDS) toward a point on or in front: forward.
ONYM, on'im, _n._ (_zool._) the technical name of a species or other group.--_adjs._ ON'YMAL, ONYMAT'IC.--_v.i._ ON'YMISE.--_n._ ON'YMY, the use of onyms.
ONYX, on'iks, _n._ (_min._) an agate formed of layers of chalcedony of different colours, used for making cameos.--_ns._ ONYCH'IA, suppurative inflammation near the finger-nail; ONYCH[=I]'TIS, inflammation of the soft parts about the nail; ONYCH'IUM, a little claw; ON'YCHOMANCY, divination by means of the finger-nails; ONYCHON[=O]'SOS, disease of the nails.--_adj._ ONYCHOPATH'IC, affected with such.--_n._ ONYCH[=O]'SIS, disease of the nails. [L.,--Gr. _onyx_, _onychos_, a finger-nail.]
OODLES, [=oo]'dlz, _n._ (_U.S._) abundance.--Also OOD'LINS.
OOF, [=oo]f, _n._ (_slang_) money.
OoGENESIS, [=o]-[=o]-jen'e-sis, _n._ the genesis and development of the ovum--also OoG'ENY.--_adj._ OoGENET'IC.
OoIDAL, [=o]-oi'dal, _adj._ egg-shaped.
OoLITE, [=o]'o-l[=i]t, _n._ (_geol._) a kind of limestone, composed of grains like the eggs or roe of a fish.--_adjs._ OoLIT'IC; OoLITIF'EROUS.
[Gr. _[=o]on_, an egg, _lithos_, stone.]
OoLOGY, [=o]-ol'o-ji, _n._ the science or study of birds' eggs.--_n._ O'oGRAPH, a mechanical device for drawing the outline of a bird's egg.--_adjs._ OoLOG'IC, -AL.--_adv._ OoLOG'ICALLY.--_ns._ OoL'OGIST, one versed in oology; OoM'ETER, an apparatus for measuring eggs.--_adj._ OoMET'RIC.--_n._ OoM'ETRY, the measurement of eggs. [Gr. _[=o]on_, an egg.]
OOLONG, [=oo]'long, _n._ a variety of black tea, with the flavour of green.--Also OU'LONG.
OORIE, OURIE, [=oo]'ri, _adj._ (_Scot._) feeling cold or chill, shivering.
OOZE, [=oo]z, _n._ soft mud: gentle flow, as of water through sand or earth: a kind of mud in the bottom of the ocean: the liquor of a tan vat.--_v.i._ to flow gently: to percolate, as a liquid through pores or small openings.--_adj._ OOZ'Y, resembling ooze: slimy. [M. E. _wose_--A.S.
_wase_, mud; akin to A.S. _wos_, juice, Ice. _vas_, moisture.]
OPACITY, [=o]-pas'i-ti, _n._ opaqueness: obscurity.
OPACOUS, [=o]-p[=a]'kus, _adj._ Same as OPAQUE.
OPAH, [=o]'pa, _n._ a sea-fish of the Dory family--also called _Kingfish_.
OPAL, [=o]'pal, _n._ a precious stone of a milky hue, remarkable for its changing colours.--_n._ OPALESC'ENCE.--_adjs._ OPALESC'ENT, reflecting a milky or pearly light from the interior; O'PALINE, relating to, or like, opal.--_v.t._ O'PALISE. [Fr. _opale_--L. _opalus_.]
OPAQUE, [=o]-p[=a]k', _adj._ shady: dark: that cannot be seen through: not transparent.--_adv._ OPAQUE'LY.--_n._ OPAQUE'NESS, quality of being opaque: want of transparency. [Fr.,--L. _opacus_.]
OPE, [=o]p, _v.t._ and _v.i._ (_poet._) short for _open_.
OPEIDOCOPE, [=o]-p[=i]'d[=o]-sk[=o]p, _n._ an instrument for illustrating sound by means of light.
OPEN, [=o]'pn, _adj._ not shut: allowing one to pass out or in: free from trees: not fenced: not drawn together: spread out: not frozen up: not frosty: free to be used, &c.: public: without reserve: frank: easily understood: generous: liberal: clear: unbalanced, as an account: attentive: free to be discussed.--_v.t._ to make open: to remove hinderances: to bring to view: to explain: to begin.--_v.i._ to become open: to unclose: to be unclosed: to begin to appear: to begin.--_n._ a clear space.--_n._ O'PENER.--_adjs._ O'PEN-EYED (_Shak._), watchful; O'PEN-HAND'ED, with an open hand: generous: liberal.--_n._ O'PEN-HAND'EDNESS.--_adj._ O'PEN-HEART'ED, with an open heart: frank: generous.--_ns._ O'PEN-HEART'EDNESS, liberality: generosity: frankness: candour; O'PENING, an open place: a breach: an aperture: beginning: first appearance: opportunity.--_adv._ O'PENLY.--_adj._ O'PEN-MIND'ED, free from prejudice: ready to receive and consider new ideas.--_n._ O'PEN-MIND'EDNESS.--_adj._ O'PEN-MOUTHED, gaping: greedy: clamorous.--_ns._ O'PENNESS; O'PEN-SES'AME, a form of words which makes barriers fly open--from the story of Ali Baba and the Forty Thieves in the _Arabian Nights' Entertainments_; O'PEN-STEEK (_Scot._), a kind of open-work stitching; O'PEN-WORK, any work showing openings through it for ornament.--_adj._ open-cast, of mining work in open air.--OPEN VERDICT (see VERDICT). [A.S. _open_--_up_, up; cf. Dut.
_open_--_op_, Ice. _opinn_--_upp_, and Ger. _offen_--_auf_.]
OPERA, op'[.e]r-a, _n._ a musical drama: a place where operas are performed.--_adj._ used in or for an opera, as an _opera_-glass, &c.--_ns._ OP'ERA-CLOAK, a cloak of elegant form and material for carrying into the auditorium of a theatre or opera-house as a protection against draughts; OP'ERA-DANC'ER, one who dances in ballets introduced into operas; OP'ERA-GLASS, a small glass or telescope for use at operas, theatres, &c.; OP'ERA-HAT, a hat which can be made flat by compression and expanded again to its full size; OP'ERA-HOUSE, a theatre where operas are represented; OP'ERA-SING'ER.--_adjs._ OPERAT'IC, -AL, pertaining to or resembling the opera. [It.,--L. _opera_. Cf. _Operate_.]
OPERA-BOUFFE, op'[.e]r-a-b[=oo]f, _n._ a comic opera. [Fr.,--It.
_opera-buffa_. Cf. _Buffoon_.]
OPERATE, op'[.e]r-[=a]t, _v.i._ to work: to exert strength: to produce any effect: to exert moral power: (_med._) to take effect upon the human system: (_surg._) to perform some unusual act upon the body with the hand or an instrument.--_v.t._ to effect: to produce by agency.--_n._ OPERAM'ETER, an instrument for indicating the number of movements made by a part of a machine.--_adj._ OP'ERANT, operative.--_n._ an operator.--_n._ OPER[=A]'TION, art or process of operating, or of being at work: that which is done or carried out: agency: influence: method of working: action or movements: surgical performance.--_adj._ OP'ER[=A]TIVE, having the power of operating or acting: exerting force: producing effects: efficacious.--_n._ a workman in a manufactory: a labourer.--_adv._ OP'ER[=A]TIVELY.--_ns._ OP'ER[=A]TIVENESS; OP'ER[=A]TOR, one who, or that which, operates or produces an effect: (_math._) a letter, &c., signifying an operation to be performed. [L. _oper[=a]ri_, _-[=a]tus_--_opera_, work, closely conn. with _opus_, _operis_, work.]
OPERCULUM, [=o]-p[.e]r'k[=u]-lum, _n._ (_bot._) a cover or lid: (_zool._) the plate over the entrance of a shell: the apparatus which protects the gills of fishes:--_pl._ OPER'CULA.--_adjs._ OPER'CULAR, belonging to the operculum; OPER'CULATE, -D, having an operculum; OPERCULIF'EROUS; OPER'CULIFORM; OPERCULIG'ENOUS; OPERCULIG'EROUS. [L.,--_oper[=i]re_, to cover.]
OPERETTA, op-[.e]r-et'a, _n._ a short, light musical drama. [It., dim. of _opera_.]
OPEROSE, op'[.e]r-[=o]z, _adj._ laborious: tedious.--_adv._ OP'EROSELY.--_ns._ OP'EROSENESS, OPEROS'ITY.
OPHICLEIDE, of'i-kl[=i]d, _n._ a large bass trumpet, with a deep pitch.
[Fr.; coined from Gr. _ophis_, a serpent, _kleis_, _kleidos_, a key.]