Give everything back to (5)
I believe the answer is:
allot
'give' is the definition.
(allotting is a kind of giving)
'everything back to' is the wordplay.
'everything' becomes 'all' (all things).
'back' is a reversal indicator.
'to' in reverse letter order is 'ot'.
'all'+'ot'='ALLOT'
(Other definitions for allot that I've seen before include "Allocate" , "grant" , "deal" , "Earmark" , "Apportion, share" .)