Elvira's finished with him! (3)
I believe the answer is:
ira
'him' is the definition.
'elvira's finished with' is the wordplay.
'with' indicates the answer is hidden within the clue.
'IRA' is hidden within 'elviras finished'.
(Other definitions for ira that I've seen before include "Illegal organisation, in short" , "Militant republicans" , "Illegal organisation, initially" , "George Gershwin's older brother, the lyricist" , "nationalists" .)