Source : Webster's Revised Unabridged Dictionary (1913)

Gamecock \Game"cock`\ (-k[o^]k`), n. (Zo["o]l.)
   The male game fowl.

Source : WordNet®

gamecock
     n 1: a cock bred and trained for fighting [syn: {fighting cock}]
     2: someone who is a very fierce fighter [syn: {hell-kite}, {hell-rooster}]