Chapter Ontogenesis to Open of O by Webster's Dictionary (1913 Edition)

Onychomancy
(On"y*cho*man`cy) n. [Gr. a finger nail + -mancy: cf. F. onychomancie.] Divination by the nails.

Onychophora
(||On`y*choph"o*ra) n. pl. [NL., from Gr. a claw + .] (Zoöl.) Malacopoda.

Onyx
(O"nyx) n. [L., fr. Gr. a claw, finger nail, a veined gem. See Nail, and cf. Onycha.] (Min.) Chalcedony in parallel layers of different shades of color. It is used for making cameos, the figure being cut in one layer with the next as a ground.

Onyx marble, a banded variety of marble or calcium carbonate resembling onyx. It is obtained from Mexico.

Oo
(Oo), a. One. [Obs.] Chaucer.

Oö
(||O"ö) n. [Hawaiian.] (Zoöl.) A beautiful bird (Moho nobilis) of the Hawaiian Islands. It yields the brilliant yellow feathers formerly used in making the royal robes. Called also yellow-tufted honeysucker.

Oœcium
(||O*œ"ci*um) n.; pl. Oœcia [NL., fr. Gr. w,'o`n an egg + a house.] (Zoöl.) One of the special zooids, or cells, of Bryozoa, destined to receive and develop ova; an ovicell. See Bryozoa.

Oögenesis
(O`ö*gen"e*sis) n. [Gr. w,'o`n an egg + E. genesis.] (Physiol.) The development, or mode of origin, of the ova.

Oögonium
(||O`ö*go"ni*um) n.; pl. L. Oögonia E. Oögoniums [NL., fr. Gr. w,'o`n an egg + offspring.] (Bot.) A special cell in certain cryptogamous plants containing oöspheres, as in the rockweeds and the orders Vaucherieæ and Peronosporeæ.

Ooidal
(O*oi"dal) a. [Gr. w,'o`n an egg + form.] (Biol.) Shaped like an egg.

Ook
(Ook) n. Oak. [Obs.] "A branched ook." Chaucer.

Oölite
(O"ö*lite) n. [Gr. w,'o`n an egg + -lite: cf.F. oölithe. So named from its resemblance to the roe of fish.] (Geol.) A variety of limestone, consisting of small round grains, resembling the roe of a fish. It sometimes constitutes extensive beds, as in the European Jurassic. See the Chart of Geology.

Oölitic
(O`ö*lit"ic) a. [Cf.F. oölithique.] Of or pertaining to oölite; composed of, or resembling, oölite.

Oölogical
(O`ö*log"ic*al) a. (Zoöl.) Of or pertaining to oölogy.

Oölogist
(O*öl"o*gist) n. One versed in oölogy.

Oölogy
(O*öl"o*gy) n. [Gr. w,'o`n an egg + -logy.] The science of eggs in relation to their coloring, size, shape, and number.

Oolong
(Oo"long) n. [Chinese, green dragon.] A fragrant variety of black tea having somewhat the flavor of green tea. [Written also oulong.]

Oomiac
(Oo"mi*ac, Oo"mi*ak) n. A long, broad boat used by the Eskimos.

Oon
(Oon) a. One. [Obs.] Chaucer.

Oones
(Oones) adv. Once. [Obs.] Chaucer.

Oop
(Oop) v. t. [Etymol. uncertain.] To bind with a thread or cord; to join; to unite. [Scot.] Jamieson.

Oopack
(Oo"pack, Oo"pak) n. [So named from a district in China.] A kind of black tea.