189 entries under severe topic. ×

4
acute
4
adamantine(adjective, set, strong, hard, tough)
4
bleak(adjective, tough, harsh, cruel)
4
brisk(adjective, stringent, drastic)
4
crisp
4
determined(adjective, harsh, solid, intense)
4
disciplined
4
exhausting(adjective, hard, tough, rough)
4
flinty(adjective, strong, hard, tough)
4
hidebound(adjective, obstinate, stubborn, unbending)
4
icy
4
intemperate(adjective, hard, tough, rough)
4
prudish(adjective, tough, firm, harsh)
4
steely(adjective, set, strong, hard, tough)
4
strait-laced(adjective, tough, firm, harsh)
4
strenuous(adjective, hard, tough, rough)
4
strong(adjective, hard, tough, sturdy)
4
stubborn(adjective, strong, hard, tough)
3
authoritarian(adjective, strong, hard, tough)
3
caustic
10 years ago|17k views|share |citing 
APASmart Define. (2016). rigorous thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/rigorous/thesaurus/synonyms
ChicagoSmart Define. 2016. "rigorous thesaurus" https://smartdefine.org/rigorous/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, rigorous thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/rigorous/thesaurus/synonyms>.
MLASmart Define. "rigorous thesaurus" 26 February 2016. Web. 23 September 2026. <https://smartdefine.org/rigorous/thesaurus/synonyms>