Final month with gold furnishings (5)
I believe the answer is:
decor
'furnishings' is the definition.
(I've seen this before)
'final month with gold' is the wordplay.
'final month' becomes 'dec' (abbreviation for December**).
'with' means one lot of letters go next to another.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'dec'+'or'='DECOR'
(Other definitions for decor that I've seen before include "Interior layout and furnishings" , "Credo (anag.)" , "(Room) design" , "Style of furnishings, drapes etc used in a room" , "Interior colour scheme and furnishing" .)