Pupil hasn't started rewarding activity (6)
I believe the answer is:
earner
'rewarding activity' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'pupil hasn't started' is the wordplay.
'pupil' becomes 'learner' (I've seen this in another clue).
'hasn't started' means to remove the first letter.
'learner' with its initial letter removed is 'EARNER'.
Can you help me to learn more?
(Other definitions for earner that I've seen before include "The one who brings home the money" , "Money-making activity" , "Breadwinner" , "Worker with income" , "One receiving income (for work)" .)