Plunder fire axe (4)
I believe the answer is:
sack
This clue is a triple definition!
'plunder' is the first definition.
(synonyms)
'fire' is the second definition.
(dismiss someone from their job)
'axe' is the third definition.
(both can mean to dismiss or fire)
(Other definitions for sack that I've seen before include "Wine; fire; bag" , "present holder" , "Dismiss (from a job)" , "Receptacle" , "Fire - rifle" .)