A zip or zip fastener is a device used to open and close parts of clothes and bags. It consists of two rows of metal or plastic teeth which separate or fasten together as you pull a small tag along them.
"it looked like nothing I had ever seen before""reduced to nil all the work we had done""we racked up a pathetic goose egg""it was all for naught""I didn't hear zilch about it"
2. a fastener for locking together two toothed edges by means of a sliding tab