Source : Webster's Revised Unabridged Dictionary (1913)

Cisco \Cis"co\, n. (Zo["o]l.)
   The Lake herring ({Coregonus Artedi}), valuable food fish of
   the Great Lakes of North America. The name is also applied to
   {C. Hoyi}, a related species of Lake Michigan.

Source : WordNet®

Coregonus artedi
     n : important food fish of cold deep lakes of North America
         [syn: {cisco}, {lake herring}]