cheerfulness cheerfulness /ˈtʃɪrfəlnəs/

noun

1. () The quality of being cheerful and dispelling gloom  ( cheer , sunniness , sunshine , cheerfulness )
   the quality of being cheerful and dispelling gloom
    Flowers added a note of cheerfulness to the drab room
   flowers added a note of cheerfulness to the drab room
   
2. A feeling of spontaneous good spirits  ( blitheness , cheerfulness )
   a feeling of spontaneous good spirits
    His cheerfulness made everyone feel better
   his cheerfulness made everyone feel better