Source : Webster's Revised Unabridged Dictionary (1913)

Bowfin \Bow"fin`\, n. (Zo["o]l.)
   A voracious ganoid fish ({Amia calva}) found in the fresh
   waters of the United States; the mudfish; -- called also
   {Johnny Grindle}, and {dogfish}.

Source : WordNet®

bowfin
     n : primitive long-bodies carnivorous freshwater fish with a
         very long dorsal fin; found in sluggish waters of North
         America [syn: {grindle}, {dogfish}, {Amia calva}]