Source : Webster's Revised Unabridged Dictionary (1913)

Loach \Loach\, n. [OE. loche, F. loche.] (Zo["o]l.)
   Any one of several small, fresh-water, cyprinoid fishes of
   the genera {Cobitis}, {Nemachilus}, and allied genera, having
   six or more barbules around the mouth. They are found in
   Europe and Asia. The common European species ({N.
   barbatulus}) is used as a food fish.

Source : WordNet®

loach
     n : slender freshwater fishes of Eurasia and Africa resembling
         catfishes