Poker type (4)
I believe the answer is:
stud
'poker type' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stud that I've seen before include "Stallion for breeding - fastener" , "Removable collar button" , "Collar fastener or horse farm" , "Ornamental protuberance" , "Football boot's peg-like projection" .)