A heady trophy (5)
I believe the answer is:
scalp
'trophy' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for scalp that I've seen before include "Hirsute war trophy once taken by Native Americans" , "Hair producer" , "Clasp (anag)" , "Track, way" , "Trophy signifying conquest" .)