Gallery area briefly accommodating knave (6)
I believe the answer is:
arcade
'gallery' is the definition.
(I've seen this in another clue)
'area briefly accommodating knave' is the wordplay.
'briefly' means to remove the last letter.
'accommodating' indicates putting letters inside.
'knave' becomes 'cad' (I've seen this in another clue).
'area' with its final letter taken off is 'are'.
'are' placed around 'cad' is 'ARCADE'.
(Other definitions for arcade that I've seen before include "Covered walkway with shops" , "Covered passage with shops on both sides" , "Covered passageway with shops and stalls" , "shopping area" , "Covered walk with shops" .)