Exam some scholar once rejected (4)
I believe the answer is:
oral
'exam' is the definition.
(spoken academic test)
'some scholar once rejected' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'rejected' says the letters should be written backwards.
'laro' is hidden within 'scholar once'.
'laro' reversed gives 'ORAL'.
(Other definitions for oral that I've seen before include "Spoken rather than written" , "Exam using speech" , "Said - form of test" , "Like some tradition" , "Spoken test" .)