Prosecuted woman, on the day (4)
I believe the answer is:
sued
'prosecuted' is the definition.
(I've seen this before)
'woman on the day' is the wordplay.
'woman' becomes 'sue' (**).
'on' says to put letters next to each other.
'the day' becomes 'd'.
'sue'+'d'='SUED'
(Other definitions for sued that I've seen before include "Started legal proceedings against (someone)" , "taken to court" , "Took legal action against" , "Prosecuted" , "Brought an action against" .)