Gold on the rise in fashionable club (4)
I believe the answer is:
iron
'club' is the definition.
(type of golf club)
'gold on the rise in fashionable' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'on the rise' shows that the letters should be reversed in order (in a down clue, letters go up).
'in' is an insertion indicator.
'fashionable' becomes 'in' (in can mean fashionable or trendy).
'or' back-to-front is 'ro'.
'ro' going inside 'in' is 'IRON'.
(Other definitions for iron that I've seen before include "Remove creases from" , "great strength" , "Main component of steel" , "used in the evening" , "Revolver" .)