119 entries under severe topic. ×

5
strenuous(adjective, hard, rough, difficult)
4
firm(adjective, strong, hard, tough)
4
relentless(adjective, close, strong, hard, tough)
4
rigid(adjective, strong, hard, tough)
4
set(adjective, strong, firm, thoughtful)
4
subdued(adjective, calm, quiet, gentle)
4
violent(adjective, hard, rough, difficult)
3
capital(adjective, important, significant, critical)
3
dull(adjective, tough, dark, gloomy)
3
frowning(adjective, strong, hard, tough)
3
poor(adjective, intense, extreme, grave)
3
quiet(adjective, calm, cool, gentle)
3
unbending(adjective, close, strong, hard, tough)
3
unyielding(adjective, strong, hard, tough)
2
bullheaded(adjective, strong, hard, tough)
2
deadpan(adjective, set, tough, honest)
2
dreadful(adjective, intense, unpleasant, horrible)
2
forbidding(adjective, close, strong, hard, tough)
2
harsh(adjective, strong, hard, tough)
2
hazardous(adjective, bad, heavy, significant)
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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>