Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
uncheerful is an adjective meaning "causing sad feelings of gloom and inadequacy". It carries one recorded sense.
causing sad feelings of gloom and inadequacy
“the economic outlook is depressing”
“something cheerless about the room”
“a moody and uncheerful person”
“an uncheerful place”
Definitions, synonyms and semantic relations for uncheerful come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.