The Collaborative International Dictionary of English v.0.48:

Blue jay \Blue" jay`\ (Zool.)
   The common jay of the United States (Cyanocitta, or Cyanura,
   cristata). The predominant color is bright blue.
   [1913 Webster]

WordNet (r) 3.0 (2006):

blue jay
    n 1: common jay of eastern North America; bright blue with grey
         breast [syn: blue jay, jaybird, Cyanocitta cristata]