Says entitled fellow going by is doing better than them (10)
I believe the answer is:
surpassing
'says entitled fellow' is the definition.
I can't tell whether this defines the answer.
'going by is doing better than them' is the wordplay.
I cannot quite see how this works, but
'going' could be 'passing' ('pass' can be a synonym of 'go') and 'passing' is located in the answer.
The remaining letters 'sur' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for surpassing that I've seen is " Being better than".)