Patching battered headgear (8)
I believe the answer is:
nightcap
'headgear' is the definition.
(I know that nightcap is a type of cap)
'patching battered' is the wordplay.
'battered' indicates an anagram.
'patching' is an anagram of 'NIGHTCAP'.
(Other definitions for nightcap that I've seen before include "A drink before sleep" , "Pre-bed drink" , "A drink before bed, wearing nocturnal headgear" , "Last drink before bed" , "what last drink might be" .)