cheerfulness          
noun [ U ] uk/ˈtʃɪə.fəl.nəs/ us/ˈtʃɪr.fəl.nəs/
C2 高兴,快乐;兴高采烈
the state of being happy and positive
  It's hard not to be affected by her enthusiasm and cheerfulness. 很难不被她的热情和开朗所感染。 
 His cheerfulness and modesty was rooted in a happy childhood. 他的开朗和谦虚植根于快乐的童年。 
 C2 欢快;赏心悦目
a bright, pleasant quality that makes you feel positive and happy
  The general cheerfulness and neatness of the building make it a nice place to work. 整个建筑干净整洁、赏心悦目,是一个很好的工作场所。 
 I like the cheerfulness of these yellow cushions. 我喜欢这些黄色坐垫带来的欢快气氛。 
 See: cheerful
 - More examples
 - The boy faced hazards and hardships with disarming cheerfulness.
 - They think that cheerfulness and optimism are the keys not only to success in life and in business, but also to a person's health and well-being.
 - Despite the long hours the staff puts in, there's a remarkable cheerfulness about the place.
 - This is one of the darkest works by a composer not exactly famed for his cheerfulness.
 - We chose these colours for their cheerfulness.
 
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