Annoy former spouse after five (3)
I believe the answer is:
vex
'annoy' is the definition.
(I know that annoy can be written as vex)
'former spouse after five' is the wordplay.
'former spouse' becomes 'ex' (an ex-spouse).
'after' says to put 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" .)