1310, common European bird (
Garrulus glandarinus), from O.Fr.
gai, from L.L.
gaius "a jay," probably echoic and supposedly infl. by L.
Gaius, a common proper name. For other bird names from proper names, cf.
martin and
parrot. Applied to the N.Amer. blue jay (
Cyanocitta cristata) from 1709. Applied to humans in sense of "impertinent chatterer, flashy dresser" from 1623.
Jaywalker is first attested 1916 in Amer.Eng. (supposedly originally in Boston), from notion of boldness and impudence.
Jayhawker is Amer.Eng., 1858, originally "freebooter, guerrilla, Kansas irregular" (esp. one who came from the North).
Jay was slang for "fourth-rate, worthless" (1888) cf.
a jay town.