Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
show-off is a noun meaning "someone who deliberately behaves in such a way as to attract attention". It carries one recorded sense.
someone who deliberately behaves in such a way as to attract attention
Definitions, synonyms and semantic relations for show-off come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.