Word Origin & History
lunatic (adj.)
c.1290, "affected with periodic insanity, dependent on the changes of the moon," from O.Fr. lunatique "insane," from L. lunaticus "moon-struck," from luna "moon." Cf. O.E. monseoc "lunatic," lit. "moon-sick;" M.H.G. lune "humor, temper, mood, whim, fancy" (Ger. Laune), from L. luna. Cf. also N.T. Gk. seleniazomai "be epileptic," from selene "moon." The noun meaning "lunatic person" is first recorded 1377. Lunatic fringe (1913) was apparently coined by U.S. politician Theodore Roosevelt. Lunatic soup (1933) was Australian slang for "alcoholic drink."