late 14c., "to lay (a crime, duty, obligation, etc.) to the account of," from Old French imposer "put, place; impute, charge, accuse" (c. 1300), from assimilated form of in- "into, in" (from PIE root *en "in") + poser "put, place" (see pose (v.1)). From c. 1500 as "apply authoritatively." Sense of "lay on as a burden, inflict by force or authority" first recorded 1580s. Related: Imposed; imposer; imposing.
