Word parts cheerful + -ness Pronunciation (US) IPA (key): /ˈt͡ʃɪrfəlnəs/ (UK) IPA (key): /ˈt͡ʃɪəfəlnəs/ Hyphenation: cheer‧ful‧ness Noun Singular cheerfulness Plural none The cheerfulness of a person is how cheerful they are.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads