An eel-like fish of the genus Ophidion (or Ophidium), or (formerly) of the family Ophidiidae; a cusk-eel; (also) the genus itself.

One or other of certain fishes (see quots.) having some resemblance to a snake.

Any of a numerous group of mostly deep-sea or cave-dwelling fishes placed either in the cusk-eel family, Ophidiidae, or separated as the Brotulidae.

any of a number of mostly small deep-sea fishes of the family Ophidiidae, having modified whisker-like fins under the throat.