189 entries under severe topic. ×

17
stiff(adjective, hard, rough, difficult)
16
nice(noun, adjective, feature, correct, slight)
15
uncompromising(adjective, hard, rough, difficult)
15
unyielding(adjective, strong, hard, tough)
12
difficult(adjective, hard, rough, harsh)
12
right(noun, adjective, hard, complete, correct)
11
tough(adjective, strong, hard, rough)
10
obdurate(adjective, strong, hard, tough)
10
sharp(noun, adjective, correct, harsh)
10
tight(adjective, careful, rigid, strict)
9
bitter(adjective, strong, hard, tough)
9
oppressive(adjective, hard, tough, rough)
8
arduous(adjective, hard, tough, rough)
8
inclement(adjective, hard, tough, rough)
8
relentless(adjective, strong, hard, tough)
8
rough(adjective, strong, hard, tough)
8
rugged(adjective, strong, hard, tough)
8
unbending(adjective, strong, hard, tough)
7
brutal(adjective, hard, tough, rough)
7
critical(adjective, harsh, precise, rigid)
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APASmart Define. (2016). rigorous thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/rigorous/thesaurus/synonyms
ChicagoSmart Define. 2016. "rigorous thesaurus" https://smartdefine.org/rigorous/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, rigorous thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/rigorous/thesaurus/synonyms>.
MLASmart Define. "rigorous thesaurus" 26 February 2016. Web. 22 September 2026. <https://smartdefine.org/rigorous/thesaurus/synonyms>