sea horse

Short definition from Wiktionary

Noun

1. 1
   Any of the small marine fish of the genus Hippocampus that have a horselike head and swim upright.
2. 2
   The walrus.
3. 3
   Synonym of hippocampus.
4. 4
   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.
5. 5
   A hippopotamus.
6. 6
   Alternative spelling of sea horse.