The Collaborative International Dictionary of English v.0.48:

Cannibal \Can"ni*bal\, n. [Cf. F. cannibale. Columbus, in a
   letter to the Spanish monarchs written in Oct., 1498,
   mentions that the people of Haiti lived in great fear of the
   Caribales (equivalent to E. Caribbees.), the inhabitants of
   the smaller Antilles; which form of the name was afterward
   changed into NL. Canibales, in order to express more forcibly
   their character by a word intelligible through a Latin root
   "propter rabiem caninam anthropophagorum gentis." The
   Caribbees call themselves, in their own language. Calinago,
   Carinago, Calliponam, and, abbreviated, Calina, signifying a
   brave, from which Columbus formed his Caribales.]
   A human being that eats human flesh; hence, any that devours
   its own kind. --Darwin.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cannibal \Can"ni*bal\, a.
   Relating to cannibals or cannibalism. "Cannibal terror."
   --Burke.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cannibal
    n 1: a person who eats human flesh [syn: cannibal, man-
         eater, anthropophagus, anthropophagite]

The Devil's Dictionary (1881-1906):

CANNIBAL, n.  A gastronome of the old school who preserves the simple
tastes and adheres to the natural diet of the pre-pork period.