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