Raised permission to study in return (8)
I believe the answer is:
leavened
'raised' is the definition.
(similar in meaning)
'permission to study in return' is the wordplay.
'permission' becomes 'leave' (leave is permission or authorisation).
'to study' becomes 'den' (den can mean an office or study).
'in return' shows that the letters should be reversed in order (return can mean to go backwards).
'den' in reverse letter order is 'ned'.
'leave'+'ned'='LEAVENED'
(Other definitions for leavened that I've seen before include "transformed for the better?" , "Of bread, containing substance that causes fermentation in dough" , "In a ferment" , "made to rise" , "With substance added that produces fermentation in dough" .)