ONYX
O"nyx, n. Etym: [L., fr. Gr. Nail, and cf. Onycha.] (Min.)
Defn: 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.
Defn: One. [Obs.] Chaucer.
OO
O"ö, n. Etym: [Hawaiian.] (Zoöl.)
Defn: 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.
OOECIUM
O*oe"ci*um, n.; pl. Ooecia. Etym: [NL., fr. Gr. (Zoöl.)
Defn: One of the special zooids, or cells, of Bryozoa, destined to receive and develop ova; an ovicell. See Bryozoa.
OOGENESIS; OOEGENESIS
O`ö*gen"e*sis, n. Etym: [Gr. genesis.] (Physiol.)
Defn: The development, or mode of origin, of the ova.