Cocked hat (7)
I believe the answer is:
tricorn
'cocked hat' is the definition.
(tricorn is a kind of cocked hat)
This is the entire clue.
(Other definitions for tricorn that I've seen before include "Cocked hat with brim turned up on three sides" , "Type of cocked hat" , "Hat with upturned brim" , "Three-cornered, hat perhaps" , "headgear" .)