Protective headgear (6)
'protective headgear' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for helmet that I've seen before include "to provide capital protection" , "Biker's headgear" , "Safety hat" , "Tin hat" , "Top Gear" .)
'protective headgear' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sunhat that I've seen before include "Summer head protector" , "Protective headgear" , "Broad-brimmed summer titfer" , "Haunts (anag.)" .)