Some average men did better (5)
I believe the answer is:
emend
'better' is the definition.
(I know that emend is a type of better)
'some average men did' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'EMEND' is hidden within 'average men did'.
(Other definitions for emend that I've seen before include "Improve (texts)" , "would appear better" , "Alter to improve (text)" , "Correct, revise (text)" , "make an improvement" .)