Benefactor: fellow appearing with gold (5)
I believe the answer is:
donor
'benefactor' is the definition.
(donor is a kind of benefactor)
'fellow appearing with gold' is the wordplay.
'fellow' becomes 'don' (I've seen this before**).
'appearing with' says to put letters next to each other.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'don'+'or'='DONOR'
(Other definitions for donor that I've seen before include "Maker of gift" , "One who gives something" , "Philanthropist" , "One who gives, perhaps blood" , "patron" .)