/ Dictionary / Index P pop-in: Meaning and Definition of Find definitions for: pop-in Pronunciation: (pop'in"), [key] — adj. requiring only a quick insertion into a receptacle to be ready for use: pop-in film cassettes; a pop-in frozen dinner. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pop-in (Thesaurus) popgun popinac Related Content Daily Word Quiz: exemplary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language