any marine teleost fish of the temperate and tropical genus Hippocampus, having a bony-plated body, a prehensile tail, and a horselike head and swimming in an upright position: family Syngnathidae (pipefishes)
2. an archaic name for the walrus
3.
a fabled sea creature with the tail of a fish and the front parts of a horse
sea horse in American English
1.
any of a genus (Hippocampus) of small, semitropical, marine bony fishes of the same family (Syngnathidae, order Gasterosteiformes) as the pipefishes, havinga slender prehensile tail, plated body, and a head and foreparts somewhat suggestive of those of a horse: it normally swims in an upright position, and the male incubates the eggs in a pouch in his abdomen