'after all' definitions:

Definition of 'after all'

From: WordNet
adverb
Emphasizes something to be considered; "after all, she is your boss, so invite her"; "he is, after all, our president"
adverb
In spite of expectations; "came to the party after all"; "it didn't rain after all"

Synonyms of 'after all'

From: Moby Thesaurus