Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
sum-up is a noun meaning "a brief statement that presents the main points in a concise form". It carries one recorded sense.
a brief statement that presents the main points in a concise form
“he gave a summary of the conclusions”
Definitions, synonyms and semantic relations for sum-up come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.