Head abolished uniform during spring (5)
I believe the answer is:
bonce
'head' is the definition.
(informal term for a person's head)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for bonce that I've seen before include "loaf" , "Human head (informal)" , "Head - noodle" , "Nut" , "Nana" .)