Uncheerful is from un- ('not') + cheerful. Cheer comes from Old French chiere ('face, countenance'), from Late Latin cara ('face'), perhaps from Greek kara ('head'). Important recorded forms include un- (Old English), chiere (Old French), and cara (Latin). Morphologically, the un- element marks negation, reversal, removal, or deprivation, while the base supplies the action, quality, or state being denied or undone. The wording preserves that uncertainty: the older history is best read as a cautious account rather than a fully settled chain. The modern sense is largely compositional, with the historical elements narrowing into a stable English lexical item. In current use it covers not cheerful; gloomy or dispiriting. The wider family includes derived forms such as uncheerfully and uncheerfulness and related words such as cheerful, cheer, and cheerless.