Head taking over university in spring (6)
I believe the answer is:
bounce
'spring' is the definition.
(I know that spring can be written as bounce)
'head taking over university' is the wordplay.
'head' becomes 'bonce' (informal term for a person's head).
'taking over' indicates putting letters inside (inserted letters are taken over or captured).
'university' becomes 'u' (abbreviation for university).
'bonce' going around 'u' is 'BOUNCE'.
'in' acts as a link.
(Other definitions for bounce that I've seen before include "Of a cheque, send back as worthless" , "Exuberance; rebound" , "Move energetically; rebound" , "Hop like rubber ball" , "Recoil like rubber ball" .)