Starring role, it could be made for boxer? (4)
I believe the answer is:
lead
I believe this clue is a triple definition!
'starring' is the first definition.
(as in a lead performer)
'role' is the second definition.
(thesaurus)
'it could be made for boxer?' is the third definition.
(a dog lead for a boxer)
(Other definitions for lead that I've seen before include "Precede; element" , "guitar accessory?" , "Chief part, element" , "item for a dog" , "Guide by going in front" .)