ex·cuse 
(ĭk-skyz)
(ĭk-skyz)tr.v. ex·cused, ex·cus·ing, ex·cus·es
1.
a. To make allowance for; overlook or forgive: Please excuse the interruption.
b. To grant pardon to; forgive: We quickly excused the latecomer.
2.
a. To apologize for (oneself) for an act that could cause offense: She excused herself for being late.
b. To explain (a fault or offense) in the hope of being forgiven or understood; try to justify: He arrived late and excused his tardiness by blaming it on the traffic. See Synonyms at forgive.
3. To serve as justification for: Witty talk does not excuse bad manners.
4. To free, as from an obligation or duty; exempt: She was excused from jury duty because she knew the plaintiff.
5. To give permission to leave; release: The child ate quickly and asked to be excused.
n. (ĭk-skys)
Idiom: 1. An explanation offered to justify or obtain forgiveness.
2. A reason or grounds for excusing: Ignorance is no excuse for breaking the law.
3. The act of excusing.
4. A note explaining an absence.
5. Informal An inferior example: a poor excuse for a poet; a sorry excuse for a car.
Excuse me
1. Used to acknowledge and ask forgiveness for an action that could cause offense.
2. Used to request that a statement be repeated.
[Middle English excusen, ultimately (partly via Old French excuser) from Latin excūsāre : ex-, ex- + causa, lawsuit; see CAUSE.]
ex·cusa·ble adj.
ex·cusa·ble·ness n.
ex·cusa·bly adv.
ex·cuser n.