Habit of weapon-carrying chap? (7)
I believe the answer is:
garment
'habit' is the definition.
(I know that habit is a more specific form of the action garment)
'weapon-carrying chap?' is the wordplay.
'weapon' becomes 'arm' (synonyms).
'carrying' means one lot of letters goes inside another.
'chap?' becomes 'gent' (I've seen this in other clues).
'arm' put into 'gent' is 'GARMENT'.
'of' is the link.
(Other definitions for garment that I've seen before include "coat maybe" , "coat, say" , "dress, perhaps" , "Piece of clothing" , "An article of clothing (7)" .)