443 entries under adjective topic. ×

5
methodical(noun, correct, solid, perfect)
5
puritanical(tough, severe, firm, harsh)
5
raw
5
unchangeable(hard, resolute, rigid, inflexible)
5
undeviating(severe, harsh, solid, exact)
5
unsparing(strong, hard, tough, severe)
4
acrimonious(tough, severe, harsh, grim)
4
acute
4
adamantine(set, strong, hard, tough)
4
bleak(tough, severe, harsh, cruel)
4
brisk(severe, stringent, drastic)
4
challenging(difficult, awkward, thorough, demanding)
4
crisp
4
detail oriented(exact, strict, scrupulous, detailed)
4
determined(severe, harsh, solid, intense)
4
diligent
4
disciplined
4
exhausting(hard, tough, severe, rough)
4
flawless(right, perfect, exact, proper)
4
flinty(strong, hard, tough, severe)
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>