Source : Webster's Revised Unabridged Dictionary (1913)

Tench \Tench\, n. [OF. tenche, F. tanche, L. tinca.] (Zo["o]l.)
   A European fresh-water fish ({Tinca tinca}, or {T. vulgaris})
   allied to the carp. It is noted for its tenacity of life.

Source : WordNet®

tench
     n : freshwater dace-like game fish of Europe and western Asia
         noted for ability to survive outside water [syn: {Tinca
         tinca}]