countable noun seahorse A seahorse is a type of small fish which appears to swim in a vertical position and whose head looks a little like the head of a horse. 0
noun seahorse 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) 0
noun seahorse a fabled sea creature with the tail of a fish and the front parts of a horse 0
