Excuse sailor only capturing Victory's leader (7)
I believe the answer is:
absolve
'excuse' is the definition.
(thesaurus)
'sailor only capturing victory's leader' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'only' becomes 'sole' ('sole' can be a synonym of 'only').
'capturing' is an insertion indicator.
'leader' suggests taking the first letters.
The initial letter of 'victorys' is 'v'.
'sole' enclosing 'v' is 'solve'.
'ab'+'solve'='ABSOLVE'
(Other definitions for absolve that I've seen before include "Forgive sins" , "Grant remission of sins" , "Set free from guilt" , "Let off the hook" , "Declare (someone) blameless" .)