Source : Webster's Revised Unabridged Dictionary (1913)

Catfish \Cat"fish`\, n. (Zo["o]l.)
   A name given in the United States to various species of
   siluroid fishes; as, the yellow cat (Amiurus natalis); the
   bind cat ({Gronias nigrilabrus}); the mud cat ({Pilodictic
   oilwaris}), the stone cat ({Noturus flavus}); the sea cat
   ({Arius felis}), etc. This name is also sometimes applied to
   the {wolf fish}. See {Bullhrad}.

Source : WordNet®

catfish
     n 1: flesh of scaleless food fish of the southern United States;
          often farmed [syn: {mudcat}]
     2: large ferocious northern deep-sea food fishes with strong
        teeth and no pelvic fins [syn: {wolffish}, {wolf fish}]
     3: any of numerous mostly freshwater bottom-living fishes of
        Eurasia and North America with barbels like whiskers
        around the mouth [syn: {siluriform fish}]
     [also: {catfishes} (pl)]