Off-book Definition

After 5 days studying the script, Jane is now off book, and can concentrate on gesture more.

"He will glibly parse a sentence ... and repeat the catechism and whole chapters of the Bible 'off book.'"

"In all likelihood, the director will leave you alone throughout the rest of the production and focus attention on the guy who isn't off book yet."

"'So if Antigone wants to be off book, I think the rest of you should be off book too.'"