■ adjective
1》 (of a book or greetings card) containing folded pictures that rise up to form a three-dimensional scene or figure when opened.
2》 (of an electric toaster) operating so as to push up a piece of toast when it is ready.
3》 Computing (of a menu or other utility) able to be superimposed on the screen being worked on and suppressed rapidly.
■ noun
1》 Computing a ~ menu or other utility.
↘an unrequested browser window, especially one generated for the purpose of advertising.
2》 Baseball see pop 1 (sense 3).