Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
unarguable is an adjective meaning "against which no argument can be made". It carries one recorded sense.
against which no argument can be made
Definitions, synonyms and semantic relations for unarguable come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.