Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
unexceptionable is an adjective meaning "completely acceptable; not open to exception or reproach". It carries one recorded sense.
completely acceptable; not open to exception or reproach
“two unexceptionable witnesses”
“a judge's ethics should be unexceptionable”
Definitions, synonyms and semantic relations for unexceptionable come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.