Henry left college (4)
I believe the answer is:
hall
'college' is the definition.
'henry left' is the wordplay.
'henry' becomes 'hal'.
'left' becomes 'l' (common abbreviation).
'hal'+'l'='HALL'
(Other definitions for hall that I've seen before include "College dinner; passage" , "College dining room" , "Entrance area" , "Large house (linked to Dotheboys, Wildfell and Toad)" , "Large public building" .)