Poker boss (4)
I believe the answer is:
stud
I believe this is a double definition.
'poker' is the first definition.
(I know that stud is a type of poker)
'boss' is the second definition.
(both can mean a metal decoration)
(Other definitions for stud that I've seen before include "Animal kept for breeding" , "Horse-breeding establishment; jewellery item" , "Form of poker game" , "Dot" , "Large headed nail" .)