443 entries under adjective topic. ×

4
hidebound(severe, obstinate, stubborn, unbending)
4
icy
4
immutable(hard, resolute, rigid, inflexible)
4
intemperate(hard, tough, severe, rough)
4
mathematical
4
narrow
4
prudish(tough, severe, firm, harsh)
4
religious(thoughtful, sober, cautious, prudent)
4
resolute(hard, intense, rigid, inflexible)
4
steely(set, strong, hard, tough)
4
strait-laced(tough, severe, firm, harsh)
4
strenuous(hard, tough, severe, rough)
4
strong(hard, tough, severe, sturdy)
4
stubborn(strong, hard, tough, severe)
4
violent
3
authoritarian(strong, hard, tough, severe)
3
caustic
3
cautious(wary, watchful)
3
compressed
3
controlled
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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>