early 15c., "mitigation, relief," from Medieval Latin alleviationem (nominative alleviatio), noun of action from past-participle stem of alleviare "lift up, raise," figuratively "to lighten (a burden), comfort, console," from assimilated form of Latin ad "to" (see ad-) + levis "light" in weight (from PIE root *legwh- "not heavy, having little weight").