Chap concealing weapon must get something to wear (7)
I believe the answer is:
garment
'something to wear' is the definition.
'chap concealing weapon' is the wordplay.
'chap' becomes 'gent' (I've seen this in other clues**).
'concealing' means one lot of letters goes inside another.
'weapon' becomes 'arm' (I've seen this before).
'gent' going around 'arm' is 'GARMENT'.
'must get' is the link.
(Other definitions for garment that I've seen before include "Covering" , "Piece of clothing" , "dress, perhaps" , "Item of clothing" , "Vestment" .)