You're excused.
1. You may leave the room, the table, etc. (Said in response to May I be excused?) Mother: Are you finished, Tom? Tom: Yes, ma'am. Mother: You're excused. Bill (raising his hand): Can I leave the room? I have to go get my books off my bike. Teacher: You're excused. Bill: Thanks.
2. You must leave the room or the premises. (Typically said at the end of a scolding.) Father: I've heard quite enough of this nonsense, Tom. You're excused. Tom: Sorry. Andy: That is the end of this conversation. You're excused. Bob: But, there's more.
3. You are forgiven for belching or for some other breach of strict etiquette. (Said in response to Excuse me.) Tom (after belching): Excuse me. Father: You're excused. Sally: Excuse me for being so noisy. Mother: You're excused.