Transform later, possibly (5)
I believe the answer is:
alter
'transform' is the definition.
(I've seen this in another clue)
'later possibly' is the wordplay.
'possibly' is an anagram indicator.
'later' anagrammed gives 'ALTER'.
(Other definitions for alter that I've seen before include "Adapt" , "Change, modify" , "Amend" , "Bout of extravagant spending" , "Change, maybe later" .)