65 entries under serious topic. ×

11
major(adjective, great, heavy, important, significant)
10
desperate(adjective, severe, intense, important, extreme)
10
dire(adjective, severe, important, extreme)
10
great(extraordinary, heavy, important, significant, extreme)
10
risky(adjective, bad, delicate, heavy, important)
9
imperative(adjective, big, important, determined, significant)
8
necessary(adjective, big, important, significant, substantial)
7
exigent(adjective, hard, tough, difficult, big)
6
indispensable(adjective, important, original, essential)
6
instant(adjective, direct, prompt, importance, important)
5
compelling(adjective, important, essential, vital)
5
notable(adjective, great, heavy, important, lively)
5
principal(adjective, great, big, important, substantial)
4
conclusive(adjective, important, determined, significant, definite)
4
high-priority(adjective, important, vital, acute)
4
life-and-death(adjective, heavy, important, vital)
3
crying(adjective, difficult, cross, important, negative)
3
heavyweight(adjective, great, big, heavy, important)
3
integral(adjective, important, essential, basic)
3
meaningful(adjective, great, important, significant, substantial)
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APASmart Define. (2016). critical thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/critical/thesaurus/synonyms
ChicagoSmart Define. 2016. "critical thesaurus" https://smartdefine.org/critical/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2016, critical thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/critical/thesaurus/synonyms>.
MLASmart Define. "critical thesaurus" 16 February 2016. Web. 28 September 2026. <https://smartdefine.org/critical/thesaurus/synonyms>