Go Up

Forget your lines during a performance (or for a techie, forget what you're supposed to do next). Mostly this is used for actors as in "He went up during act one and we lost two pages (of script that got skipped over when he started up again)."

This is more of an acting than a technical term, but I present it here as you will probably hear actors use it from time to time. This way you will know what they are talking about.