Open English Wordnet
Nouns
(n)cheerfulness, cheer, sunniness, sunshinethe quality of being cheerful and dispelling gloom“flowers added a note of cheerfulness to the drab room”
Verbs
(v)cheer, cheer up, jolly along, jolly upcause (somebody) to feel happier or more cheerful“She tried to cheer up the disappointed child when he failed to win the spelling bee”