I gotta catch some Z's before I drop.Why don't you stop a little bit and try to cop some Z's?
cut some Z's
To get some sleep. In illustrations such as comics, three (or more) Z's are often used to represent sleep or snoring. We've got a pretty long layover before our next flight, so I'm going to try to cut some Z's at the gate.Jeff's upstairs cutting some Z's. It's been a hard week for him.