To zip is to close with a zipper. Also, zip means zilch, which is zero or nothing. Make sure to zip your wallet because if everything falls out, you’ll have zip.
Zip as in “to close with a zipper” is short for — you guessed it — zipper. If you're cold, zip up your coat. If you zip your lips, you’re not using a zipper but you’re closing your mouth. Zip meaning “nothing” came from kids in the 1900s when they referred to getting a zero on a test. Now, if you have zip, you have nothing, and not just on a test.