dolphin

noun

• 1a small gregarious toothed whale which typically has a beak-like snout and a curved fin on the back. Dolphins have become well known for their sociable nature and high intelligence.

  • Families Delphinidae (marine) and Platanistidae (the river dolphins): several genera and many species

• 2 (also dolphinfish)another term for dorado (sense 1).

• 3a bollard, pile, or buoy for mooring boats.

• 4a structure for protecting the pier of a bridge.