Source : Webster's Revised Unabridged Dictionary (1913)

Blue jay \Blue" jay`\ (Zo["o]l.)
   The common jay of the United States ({Cyanocitta, or Cyanura,
   cristata}). The predominant color is bright blue.

Source : WordNet®

blue jay
     n : common jay of eastern North America; bright blue with grey
         breast [syn: {jaybird}, {Cyanocitta cristata}]