Unprepared for war, possibly (3)
I believe the answer is:
raw
'unprepared' is the definition.
(I've seen this in another clue)
'war possibly' is the wordplay.
'possibly' is an anagram indicator.
'war' anagrammed gives 'RAW'.
'for' is the link.
(Other definitions for raw that I've seen before include "Damp and chilly" , "Callow" , "Uncooked or crude" , "not yet ready to eat" , "Not cooked" .)