sea horse

noun5

1. •
   Any of the small fish of the genus Hippocampus that have a horselike head and swim upright.
2. •
   Any of a series of high-value British stamps issued during the reign of King George V, featuring a depiction of Britannia on a chariot in choppy seas.
3. •
   Synonym of hippocampus.
4. •
   (no longer used) A hippopotamus.

   • As most authors mention the hippopotamus under the names of the sea-horse, or the sea-cow, he has sometimes been confounded with the latter, which inhabits only the northern seas. — 1830
5. •
   (no longer used) A walrus.

   • One morning we had vast quantities of sea-horses about the ship, which neighed exactly like any other horses. — 1789