B-reel noun2 •The second piece of film or audio or video tape in a situation (as editing or broadcasting) where multiple inputs are used.The separate reels of a multiple-chain story are given letter designations: A-reel, B-reel, C-reel. — 1969 •Secondary or supplemental footage to be intercut with principle film or video.Now I remembered that Murph had convinced us not to show the first B reel during our viewing of the full takes, saying that we’d seen it before. — 1991 formsB-reels
