eel a name primarily applied to fish of the genus Anguilla, which are born and die in the oceans but pass most of their lives in fresh water. However, the term is also properly applied to various marine fish which belong to the same order and have similarly shaped bodies: see conger eel; moray eel. The term also crops up in the names of some fish of other orders, e.g. the eel-pout (mutton-fish in the USA, quite good but not much eaten) and sand-eel, which share some of the characteristics of true eels. (Cusk eels and catfish eels are not true eels, but species of fish that bear some resemblance to eels, although more to cusk and catfish respectively.)
