The Collaborative International Dictionary
Hydrophid
Hydrophid \Hy"dro*phid\, n. [Hydro-, 1 + Gr. ? a small serpent.] (Zo["o]l.) Any sea snake of the genus Hydrophys and allied genera. These snakes are venomous, live upon fishes, and have a flattened tail for swimming.
Wiktionary
hydrophid
n. (context zoology English) Any sea snake of the subfamily (taxlink Hydrophiinae subfamily), venomous, preying on fishes, with a flattened tail for swimming.