HYDROZOA
Hy`dro*zo"a, n. pl. Etym: [NL., fr. E. hydra + Gr. (Zoöl.)
Defn: The Acalephæ; one of the classes of coelenterates, including the Hydroidea, Discophora, and Siphonophora.
HYDROZOAL
Hy`dro*zo"al, a. (Zoöl.)
Defn: Of or pertaining to the Hydrozoa.
HYDROZOON; HYDROZOOEN
Hy`dro*zo"ön, n.; pl. L. Hydrozoa, E. Hydrozoöns. Etym: [NL.] (Zoöl.)
Defn: One of the Hydrozoa.
HYDRURET
Hy"dru*ret, n. Etym: [Hydro-, 2] (Chem.)
Defn: A binary compound of hydrogen; a hydride. [Obs.]
HYDRUS Hy"drus, n. Etym: [L., a water serpent; also, a certain constellation, Gr. "y`dros.] (Astron.)
Defn: A constellation of the southern hemisphere, near the south pole.