Landlord entertains student composer (5)
I believe the answer is:
holst
'composer' is the definition.
(Gustav Holst)
'landlord entertains student' is the wordplay.
'landlord' becomes 'host'.
'entertains' indicates putting letters inside.
'student' becomes 'l'.
'host' going around 'l' is 'HOLST'.
(Other definitions for holst that I've seen before include "He scored" , "Scorer" , "Composer of The Planets, d. 1934" , "British composer, 1874-1934" , "Planets Suite composer" .)