Bird has fight after fight (7)
I believe the answer is:
sparrow
'bird' is the definition.
(sparrow is a kind of bird)
'fight after fight' is the wordplay.
'fight' becomes 'spar' (sparring is a kind of fighting).
'after' is a charade indicator (letters next to each other).
'fight' becomes 'row' (I've seen this in another clue).
'spar'+'row'='SPARROW'
'has' is the link.
(Other definitions for sparrow that I've seen before include "House bird" , "Small brown bird" , "Winger" , "Common small bird" , "a British resident" .)