Sorry fellow more disheartened coming below average (6,2)
I believe the answer is:
pardon me
'sorry' is the definition.
(I've seen this in another clue)
'fellow more disheartened coming below average' is the wordplay.
I cannot really see how this works, but
'fellow' could be 'don' (both can mean an academic) and 'don' is found within the answer.
'more' could be 'm' and 'm' is present in the answer.
'average' could be 'par' (average score in golf) and 'par' is located in the answer.
A single letter 'e' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for pardon me that I've seen before include "Polite apology" , "Say that again!" , "Sorry" .)