Debauched scholar, student I confine to college grounds (10)
I believe the answer is:
profligate
'debauched' is the definition.
(synonyms)
'scholar student i confine to college grounds' is the wordplay.
'scholar' becomes 'prof' (short for professor).
'student' becomes 'l' (as in L-plates for learner drivers).
'confine to college grounds' becomes 'gate' (to gate is to confine a student to school grounds).
'prof'+'l'+'i'+'gate'='PROFLIGATE'
(Other definitions for profligate that I've seen before include "Wildly extravagant" , "Wastrel" , "Husband would not be" , "Debauched" , "Recklessly wasteful" .)