hippŏcampus or -os, i, m., = ἱππόκαμπος,
a sea-horse : Syngnathus hippocampus, Linn.; Plin. 32, 11, 53, § 149; 32, 7, 23, § 67; 32, 9, 30, § 93; 36, 5, 4, § 26; Naev. and Lucil. ap. Non. 120, 17 and 19.
·noun A genus of lophobranch fishes of several species in which the head and neck have some resembla...
Webster's Dictionary of the English Language
A small fish, so termed from the head resembling that of a horse. They live among reeds and long fuc...
The Sailor's Word-Book