Uncommonly, perhaps, it goes to one's head (7)

I believe the answer is:

coronet

I'm a little stuck... Click here to teach me more about this clue!

But I can't explain it at all! Could you help me understand?

(Other definitions for coronet that I've seen before include "Peer's headgear" , "topping item of jewellery" , "badge of rank" , "emblem of rank" , "Circular floral head decoration" .)

Want a hint initially instead of a full solution? Install my app