(dol′fin) noun
1. Any of various cetaceans (family Delphinidae), with beaklike snouts; specifically, the common dolphin (Delphinus delphis), about seven feet long, of the Mediterranean and temperate Atlantic; and the bottle–nosed dolphin (Turiops truncatus) of the American Atlantic coast: loosely called porpoise.
2. Either of two fish of the genus Coryphaena of southern waters; especially, the edible C. hippurus: also called dorado.
3. Naut. a A spar or block of wood attached to an anchor and used for small boats to ride by. b A mooring post or buffer, or a series of such posts contiguous to each other. c A group of protective rope fenders just beneath the gunwale of a boat.
—adjective Of or pertaining to devices having a fancied resemblance to the dolphin. [<OF daulphin <L delphinus <Gk. delphis, -inos]
THE COMMON DOLPHIN

(dol′fin)
The constellation Delphinus. See CONSTELLATION.