Describing most of the dictionary in spite of everything (5,3)
I believe the answer is:
after all
'in spite of everything' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
(Other definitions for after all that I've seen before include "in the final reckoning?" , "I mean, when everything's said and done" , "Bringing up the rear" , "at the end of the day" , "Taking everything into account" .)