Definition of zipper noun from the Oxford Advanced Learner's Dictionary

zipper

noun
ˈzɪpə(r)
 
; ˈzɪpər
 
(especially North American English) (British English also zip, zip fastener)
 
a thing that you use to fasten clothes, bags, etc. It consists of two rows of metal or plastic teeth that you can pull together to close something or pull apart to open it.