https://www.merriam-webster.com/thesaurus/mirthlessly
MIRTHLESSLY Synonyms: 90 Similar and Opposite Words | Merriam-Webster Thesaurus
Synonyms for MIRTHLESSLY: morosely, darkly, glumly, blackly, somberly, gloomily, dourly, sullenly; Antonyms of MIRTHLESSLY: joyously, happily, joyfully,...
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