Companion of an American star (6)

I believe the answer is:

stripe

I'm a little stuck... Click here to teach me more about this clue!

'star' is the definition.
(thesaurus)

I don't understand how the remainder of the clue works.

(Other definitions for stripe that I've seen before include "Military mark of rank, chevron" , "Chevron; band" , "Long band of a different colour" , "promotion, maybe" , "Band of contrasting colour" .)

I've seen this clue in The Globe and Mail.

Want a hint initially instead of a full solution? Install my app