10
tight(adjective, severe, careful, rigid, strict)
9
bitter(adjective, strong, hard, tough, severe)
9
delicate(adjective, feature, slight, difference, truth)
9
fine(adjective, feature, slight, difference, truth)
9
minute(adjective, feature, right, slight, fine)
9
oppressive(adjective, hard, tough, severe, rough)
9
painstaking(adjective, harsh, rigid, honorable, reliable)
9
pinpoint(adjective, exact, strict, scrupulous, detailed)
8
arduous(adjective, hard, tough, severe, rough)
8
fastidious(adjective, thoughtful, precise, sober, honorable)
8
inclement(adjective, hard, tough, severe, rough)
8
neat(adjective, exact, strict, scrupulous, detailed)
8
relentless(adjective, strong, hard, tough, severe)
8
rough(adjective, strong, hard, tough, severe)
8
rugged(adjective, strong, hard, tough, severe)
8
trustworthy(adjective, exact, strict, scrupulous, detailed)
8
unbending(adjective, strong, hard, tough, severe)
7
adjusted(adjective, exact, strict, scrupulous, detailed)
7
attentive to details(adjective, exact, strict, scrupulous, detailed)
7
brutal(adjective, hard, tough, severe, rough)
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APASmart Define. (2016). rigorous thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/rigorous/thesaurus/synonyms
ChicagoSmart Define. 2016. "rigorous thesaurus" https://smartdefine.org/rigorous/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, rigorous thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/rigorous/thesaurus/synonyms>.
MLASmart Define. "rigorous thesaurus" 26 February 2016. Web. 21 September 2026. <https://smartdefine.org/rigorous/thesaurus/synonyms>