Perform by gold entrance (4)
I believe the answer is:
door
'entrance' is the definition.
(door is a kind of entrance)
'perform by gold' is the wordplay.
'perform' becomes 'do' (synonyms).
'by' is a charade indicator (letters next to each other).
'gold' becomes 'or' ('or' is the heraldic name for gold).
'do'+'or'='DOOR'
(Other definitions for door that I've seen before include "Opener" , "Means of exit and entrance" , "Alternative to knocker" , "Swinging barrier" , "Barrier to open and close" .)