Annoy former spouse after five (3)
I believe the answer is:
vex
'annoy' is the definition.
('vex' can be a synonym of 'annoy')
'former spouse after five' is the wordplay.
'former spouse' becomes 'ex'.
'after' is a charade indicator (letters next to each other).
'five' becomes 'v' (roman numeral).
'ex' after 'v' is 'VEX'.
(Other definitions for vex that I've seen before include "Irritate, annoy" , "upset" , "Irk" .)