Barbarian is wise to accept a victory (6)
I believe the answer is:
savage
'barbarian' is the definition.
('savage' can be a synonym of 'barbarian')
'wise to accept a victory' is the wordplay.
'wise' becomes 'sage' ('sage' can be similar in meaning to 'wise').
'to accept' means one lot of letters goes inside another.
'victory' becomes 'v'.
'a'+'v'='av'
'sage' placed around 'av' is 'SAVAGE'.
'is' acts as a link.
(Other definitions for savage that I've seen before include "Wild, barbarous" , "Menacing, uncivilised" , "Uncivilised, vicious" , "Viciously criticise" , "Ferocious" .)