Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
unhumorous is an adjective meaning "lacking humor". It carries one recorded sense.
lacking humor
“it was a humorless wink; a wink of warning”
Definitions, synonyms and semantic relations for unhumorous come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.