Adapt or change later (5)
I believe the answer is:
alter
'adapt' is the definition.
(I've seen this before)
'change later' is the wordplay.
'change' is an anagram indicator.
'later' anagrammed gives 'ALTER'.
'or' acts as a link.
(Other definitions for alter that I've seen before include "Change, modify" , "Bout of extravagant spending" , "Change, make different" , "Vary" , "convert" .)