1) a sealed container for magnetic tape or for photographic film (cassette)

2) (a section of) very small photographic film (microfilm)

3) (to make) a copy of (a document etc) using a photographic method (photocopy)

4) a kind of (music for a) lively Scottish dance; a long, round object on which cotton, thread, wire, photographic film, magnetic tape etc is wound (reel)

5) a round holder (for thread, wire, photographic film, magnetic tape etc) (spool)