Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
great-uncle is a noun meaning "an uncle of your father or mother". It carries one recorded sense.
an uncle of your father or mother
Definitions, synonyms and semantic relations for great-uncle come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.