Pronunciation: (dol'fin, dôl'-),[key] —n. 1. any of several chiefly marine, cetacean mammals of the family Delphinidae, having a fishlike body, numerous teeth, and the front of the head elongated into a beaklike projection.
2. Also called dolphinfish, mahimahi. either of two large, slender fishes, Coryphaena hippurus or C. equisetis, of warm and temperate seas.
3. Naut. a. a pile, cluster of piles, or buoy to which a vessel may be moored in open water.
b. a cluster of piles used as a fender, as at the entrance to a dock.
c. a pudding fender at the nose of a tugboat or on the side of a vessel.
4. (cap.) Astron.the constellation Delphinus.