Cheer and force boy to study (7)
I believe the answer is:
gladden
'cheer' is the definition.
(I've seen this before)
'force boy to study' is the wordplay.
'force' becomes 'G' (short for gravity).
'boy' becomes 'lad' (informal term for boy).
'to study' becomes 'den' (term for a study or office).
'g'+'lad'+'den'='GLADDEN'
'and' acts as a link.
(Other definitions for gladden that I've seen before include "Make joyful" , "Make pleased or happy" , "Hearten" , "raise spirits" , "Delight" .)