Hand over and retire (4,2)
I believe the answer is:
turn in
This clue is a double definition.
'hand over' is the first definition.
(both can mean to surrender or give up something)
'retire' is the second definition.
(synonyms)
'and' acts as a link.
(Other definitions for turn in that I've seen before include "Go to bed, changing direction" , "Informally, go to bed or hand over" , "Hand over - retire" , "Hit the hay" , "rat on" .)