Dwindle, with "out" (5)
I believe the answer is:
peter
'dwindle with out' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for peter that I've seen before include "Disciple" , "- Pan, eternal youth" , "prison cell" , "Safe - name for a man" , "-- Sellers, comic actor" .)