Pop-up as an adjective first appeared in the 1930s, first in relation to children’s books, later to toasters, and by the end of the 20th century as a description of menus or other utilities capable of temporarily appearing on a computer screen. The latter sense then also spawned the more regular appearance of pop-up as a countable noun.

Pop-up as an adjective first appeared in the 1930s, first in relation to children’s books, later to toasters, and by the end of the 20th century as a description of menus or other utilities capable of temporarily appearing on a computer screen. The latter sense then also spawned the more regular appearance of pop-up as a countable noun.