Word Origin & History
c.1275, gayhol, from O.N.Fr. gaiole and O.Fr. jaole, both meaning "a cage, prison," from M.L. gabiola, from L.L. caveola, dim. of L. cavea "cage." Both forms carried into M.E.; now pronounced "jail" however it is spelled. Norman-derived gaol (preferred in Britain) is "chiefly due to statutory and official
tradition" [OED]. The verb "to put in jail" is from 1604. Jailbird is 1603, an allusion to a caged bird. Jail-break "prison escape" is from 1910. Jail bait "girl under the legal age of consent" is attested from 1934.