Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
pop-up is a noun meaning "a book (usually for children) that contains one or more pages such that a three-dimensional structure rises up when a page is opened". It carries 2 recorded senses.
a book (usually for children) that contains one or more pages such that a three-dimensional structure rises up when a page is opened
baseball
Definitions, synonyms and semantic relations for pop-up come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.