1
general::
1. Despite everything, nevertheless, as in The plane took off half an hour late but landed on time after all. 2. After everything else has been considered, ultimately, as in Mary has final approval of the guest list; after all, it's her wedding. The two usages are pronounced differently, the first giving stress to the word after and the second to the word all. Both date from the early 1700s. Also see WHEN ALL IS SAID AND DONE.
American Heritage Idioms
2
general::
Phrase(s): after all
1. anyway; in spite of what had been decided. (Often refers to a change in plans or a reversal of plans.) • It looks like Tom will go to law school after all. 2. recalling or considering the fact that. • Don’t punish Tommy! After all, he’s only three years old!
McGrawhill's American Idioms And Phrasal Verbs