918 entries under adjective topic. ×

11
fateful(importance, valuable, main, notable)
11
impressive(importance, valuable, main, notable)
11
influential(good, great, importance, important)
11
notable(great, extraordinary, importance, unusual)
11
thoughtful(severe, deep, sober, thinking)
10
desperate(severe, significant, extreme, vital)
10
major(great, unpleasant, heavy, important)
10
outstanding(great, importance, unusual, important)
10
purposeful(firm, importance, resolute, valuable)
10
responsible(importance, valuable, main, notable)
10
steady(calm, set, cool, firm)
10
stern(resolute, somber, humorless)
10
terrible(bad, great, difficult, extraordinary)
9
big-league(importance, valuable, main, notable)
9
fervent(complete, keen, warm, total)
9
intense(severe, keen, warm, sensible)
9
no-nonsense(calm, dull, work, open)
9
remarkable(importance, unusual, important, famous)
9
resolute(severe, firm, sensible, harsh)
9
unsmiling(somber, humorless)
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APASmart Define. (2016). serious thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/serious/thesaurus/synonyms
ChicagoSmart Define. 2016. "serious thesaurus" https://smartdefine.org/serious/thesaurus/synonyms (accessed September 26, 2026).
HarvardSmart Define 2016, serious thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/serious/thesaurus/synonyms>.
MLASmart Define. "serious thesaurus" 24 February 2016. Web. 26 September 2026. <https://smartdefine.org/serious/thesaurus/synonyms>