Grades too devised for entrance to theatre (5,4)
I believe the answer is:
stage door
'entrance to theatre' is the definition.
I can't judge whether this defines the answer.
'grades too devised' is the wordplay.
'devised' indicates anagramming the letters.
'grades'+'too'='gradestoo'
'gradestoo' with letters rearranged gives 'STAGE-DOOR'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for stage door that I've seen before include "Company access" , "Actors' entrance" , "What players have to go through" , "Service entrance to theatre" , "Theatre rear entrance" .)