c.1300, "disease, distress, mental suffering," from O.Fr. languor, from L. languorem (nom. languor) "faintness, feebleness, lassitude," from languere "be weak or faint" (see lax). Sense shifted to "faintness, weariness" (1650s) and "habitual want of energy" (1825). Related: Languorous.
