An elongated fish of many genera and species. The common eels of Europe and America belong to the genus Anguilla. The electrical eel is a species of Gymnotus. The so called vinegar eel is a minute nematode worm. See Conger eel, Electric eel, and Gymnotus.
- Any of various long, snakelike, scaleless marine or freshwater fishes of the order Anguilliformes or Apodes that lack pelvic fins and characteristically migrate from fresh water to salt water to spawn.
- Any of several similar fishes, such as the lamprey and electric eel.