8
bad(adjective, severe, nasty, offensive, unhappy)
8
challenging(adjective, hard, tough, difficult, importance)
8
composed(adjective, calm, cool, sensible, dark)
8
determined(adjective, set, strong, firm, total)
8
dignified(adjective, calm, cool, severe, important)
8
dour(adjective, close, hard, severe, harsh)
8
good(adjective, honest, pure, important, significant)
8
historic(adjective, importance, important, main, extremely significant)
8
honest(adjective, set, open, true, natural)
8
intent(adjective, firm, determined, thoughtful, sober)
8
ruminative(adjective, reasonable, rational, thoughtful, sober)
8
somber(adjective, calm, dull, cool, severe)
7
newsworthy(adjective, importance, important, valuable, main)
7
pensive(adjective, set, keen, unhappy, gloomy)
7
austere(adjective, set, strong, hard, tough)
7
awful(adjective, bad, severe, offensive, intense)
7
big shot(adjective, importance, valuable, main, notable)
7
bigwig(adjective, importance, valuable, main, notable)
7
committed(adjective, complete, warm, total, passionate)
7
constitutive(adjective, importance, valuable, main, notable)
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APASmart Define. (2016). serious thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/serious/thesaurus/synonyms
ChicagoSmart Define. 2016. "serious thesaurus" https://smartdefine.org/serious/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, serious thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/serious/thesaurus/synonyms>.
MLASmart Define. "serious thesaurus" 24 February 2016. Web. 23 September 2026. <https://smartdefine.org/serious/thesaurus/synonyms>