Damaged gun's alright internally (6)
I believe the answer is:
broken
'damaged' is the definition.
(associated in meaning)
'gun's alright internally' is the wordplay.
'gun' becomes 'bren' (Bren is an example).
'alright' becomes 'OK' (synonyms).
'internally' indicates putting letters inside.
'bren' going around 'ok' is 'BROKEN'.
(Other definitions for broken that I've seen before include "Defective" , "Smashed or tamed" , "Interrupted; inoperative" , "If it's not ..., don't fix it" , "Busted, damaged" .)