| APA | Smart Define. (2016). cheerfulness thesaurus. Retrieved September 30, 2026, from https://smartdefine.org/cheerfulness/thesaurus/antonyms |
| Chicago | Smart Define. 2016. "cheerfulness thesaurus" https://smartdefine.org/cheerfulness/thesaurus/antonyms (accessed September 30, 2026). |
| Harvard | Smart Define 2016, cheerfulness thesaurus, Smart Define, viewed 30 September, 2026, <https://smartdefine.org/cheerfulness/thesaurus/antonyms>. |
| MLA | Smart Define. "cheerfulness thesaurus" 23 March 2016. Web. 30 September 2026. <https://smartdefine.org/cheerfulness/thesaurus/antonyms> |