Source : Webster's Revised Unabridged Dictionary (1913)

Sheatfish \Sheat"fish`\, n. [Cf. dial. G. scheid, schaid,
   schaiden.] (Zo["o]l.)
   A European siluroid fish ({Silurus glanis}) allied to the
   cat-fishes. It is the largest fresh-water fish of Europe,
   sometimes becoming six feet or more in length. See
   {Siluroid}.

Source : WordNet®

sheatfish
     n : large elongated catfish of central and eastern Europe [syn:
         {European catfish}, {Silurus glanis}]
     [also: {sheatfishes} (pl)]