dolphin Definition

any of various small marine toothed whales (family Delphinidae) with the snout more or less elongated into a beak and the neck vertebrae partially fused

any of several related chiefly freshwater toothed whales (as of the families Platanistidae and Iniidae) : river dolphin

dolphinfish

either of two colorful, iridescent, saltwater fish (Coryphaena equiselis and C. hippurus of the family Coryphaenidae) that are widely distributed in tropical and temperate seas and have a long laterally compressed body and a deeply forked tail fin

a vertical spar under the end of the bowsprit of a sailboat to extend and support the martingale

a relatively small chiefly gray toothed whale (Tursiops truncatus) of temperate to tropical waters that has a prominent beak and falcate dorsal fin, reaches a length of 6 to 12 feet (1.8 to 3.6 meters), and is typically found in groups; also : a related whale (T. aduncus) of waters of the Indian Ocean and western Pacific Ocean

a dolphin (Grampus griseus) widely distributed in temperate and tropical seas that has a blunt snout, a rounded forehead, and teeth in the lower jaw only —called also grampus

any of various small, toothed whales (as of the families Platanistidae and Iniidae) that chiefly inhabit rivers of South America and Asia and have a rounded forehead and a snout elongated into a long beak

a long-beaked dolphin (Stenella longirostris) that is typically dark gray above and white below and that is noted for its habit of spinning in the air when breaching