Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
unostentatious is an adjective meaning "not ostentatious". It carries 2 recorded senses.
not ostentatious
“his unostentatious office”
“unostentatious elegance”
exhibiting restrained good taste
“the room is pleasant and understated”
Definitions, synonyms and semantic relations for unostentatious come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.