late 14c., "let in," from Latin admittere "admit, give entrance, allow to enter; grant an audience," of acts, "let be done, allow, permit," from ad "to" (see ad-) + mittere "let go, send" (see mission). Sense of "to concede in argument as valid or true" is first recorded early 15c. In Middle English sometimes also amit, after Old French amettre, which was refashioned 15c. Related: Admitted; Admitting.
