Merriam-Webster Collegiate Dictionary - jay

 I. noun  Etymology: Middle English, from Anglo-French, from Late Latin gaius  Date: 14th century  1.  a. a predominantly fawn-colored Old World bird (Garrulus glandarius) of the crow family with a black-and-white crest and wings marked with black, white, and blue  b. any of various usually crested and largely blue chiefly New World birds that are related to the common Old World ~ and have roving habits and harsh voices — compare blue ~  2.  a. an impertinent chatterer  b. dandy 1  c. greenhorn  3. a moderate blue  II. noun  Date: circa 1889  1. the letter j  2. joint 4 JAY  biographical name John 1745-1829 American jurist & statesman; 1st chief justice United States Supreme Court (1789-95)