Headwear item (3)
'headwear item' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for cap that I've seen before include "subsidy regime" , "Soft headgear" , "Top; hat" , "Outdo; brimless hat" , "cover" .)
(Other definitions for hat that I've seen before include "One to cover head" , "Eg, bowler" , "Headdress" , "Lid" , "Item of headgear" .)
(Other definitions for baseball cap that I've seen before include "What sportsman may assume" , "American sporting headgear" , "Long-peaked headgear" , "Sports headgear" , "sportswear" .)
(Other definitions for flat cap that I've seen before include "working-class symbol" , "Style of headgear" , "> lid" , "Headgear (of the working class?)" , "Type of hat" .)