early 15c., "to misuse, misapply," from Middle French abuser, from Vulgar Latin *abusare, from Latin abusus "an abusing, using up," past participle of abuti "use up," also "misuse," from ab- "away" (see ab-) + uti "use" (see use). Of sexual situations from early 15c., but originally incest, homosexuality, prostitution, etc.; meaning "to misuse sexually, ravish" is from 1550s. Specifically of drugs, from 1968. Related: Abused; abusing.
mid-15c., "improper practice," from Old French abus (14c.), from Latin abusus (see abuse (v.)). Earlier in Middle English was abusion "wicked act or practice, shameful thing, violation of decency" (early 14c.), "an insult" (mid-14c.).