Boss of film company denied one Oscar (4)
I believe the answer is:
stud
'boss' is the definition.
(both can mean a metal decoration)
I can't explain the remainder of the clue.
(Other definitions for stud that I've seen before include "Variety of poker" , "Stallion for breeding - fastener" , "Decoration" , "Animal kept for breeding" , "Lothario" .)