Away kit, better (8)
I believe the answer is:
outstrip
'better' is the definition.
(better can mean to outstrip or outdo)
'away kit' is the wordplay.
'away' becomes 'out' (synonyms).
'kit' becomes 'strip' (I've seen this in other clues).
'out'+'strip'='OUTSTRIP'
(Other definitions for outstrip that I've seen before include "Perform better than" , "Outrun or surpass" , "Beat" , "Go far ahead of" , "Surpass, do better than" .)