Cowboy's hat (7)
I believe the answer is:
stetson
'cowboy's hat' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for stetson that I've seen before include "No tests (anag.)" , "A wide-brimmed cowboy hat" , "Hat, for Texan oil magnate, say" , "Large hat" , "Hat with broad brim and high crown" .)