Improvement at college with shift (6)
I believe the answer is:
upturn
'improvement' is the definition.
(upturn is a kind of improvement)
'at college with shift' is the wordplay.
'at college' becomes 'up'.
'with' says to put letters next to each other.
'shift' becomes 'turn' (turn is a kind of shift**).
'up'+'turn'='UPTURN'
(Other definitions for upturn that I've seen before include "Improving trend" , "Improved trend in business or fortune" , "Recovery" , "Improvement in fortunes" , "Improvement, better trend in business" .)