What is zip?
zip is (noun) a device for closing openings on clothes and bags, consisting of two rows of teeth which lock together (informal.) The zip of my anorak is broken. Can you do up the zip at the back of my dress? (NOTE: The US term is zipper.) (verb) 1. to go fast Cars were zipping past us on the motorway.2. to zip up to close something using a zip She zipped up her anorak. He zipped up his bag.
source: Easier English, Student Dictionary Upper Intermediate Level