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.
seahorse in British English
or sea horse (ˈsiːhɔːs)
noun
1.
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. archaic another name for walrus
3.
a fabled sea creature with the tail of a fish and the front parts of a horse
Examples of 'seahorse' in a sentence
seahorse
The solid mahogany door had a brass seahorse a foot long facing out of it.