Dic: after all

adv.

[1]
─ emphasizes something to be considered
─ You use after all when introducing a statement which supports or helps explain something you have just said.
─ used when you are explaining sth or giving a reason.

• after all, she is your boss, so invite her.
• he is, after all, our president.
• I thought you might know somebody. After all, you're the man with connections.
• Can’t I stay up late tonight? After all, there’s no school tomorrow!
• You got a fair price for your car. It’s six years old, after all.

[2]
─ in spite of expectations
─ You use after all when you are saying that something that you thought might not be the case is in fact the case.
─ used to show that sth is the opposite of what you first intend to do or expect to happen.

• came to the party after all
• I came out here on the chance of finding you at home after all.
• I think I will have something to eat after all.
• We could have left our coats at home — it didn’t rain after all.

..... WordNet, Cobuild, OALD