Source : Webster's Revised Unabridged Dictionary (1913)

Bull terrier \Bull" ter"ri*er\ (Zo["o]l.)
   A breed of dogs obtained by crossing the bulldog and the
   terrier.

Source : WordNet®

bull terrier
     n : a powerful short-haired terrier originated in England by
         crossing the bulldog with terriers [syn: {bullterrier}]