Synonyms|1kAntonyms|253|Broader|5Narrower|1Related|546

140 entries under hard topic. ×

2
savage(adjective, tough, harsh, unpleasant)
2
steadfast(adjective, resolute, rigid, inflexible)
2
stiff-necked(adjective, strong, tough, severe)
2
thick(adjective, strong, tough, sturdy)
2
troublesome(adjective, tough, severe, rough)
2
unadaptable(adjective, resolute, rigid, inflexible)
1
avaricious(adjective, tough, harsh, cruel)
1
backbreaking(adjective, tough, severe, rough)
1
barbarous(adjective, tough, harsh, cruel)
1
bloody(adjective, tough, harsh, cruel)
1
bullheaded(adjective, strong, tough, severe)
1
by the book(expression, adjective, idiom, strong)
1
callous(adjective, tough, harsh, grim)
1
disciplinary(adjective, strong, tough, severe)
1
dyed-in-the-wool(adjective, set, strong, tough)
1
fatiguing(adjective, tough, severe, rough)
1
forbidding(adjective, strong, tough, severe)
1
frowning(adjective, strong, tough, severe)
1
grievous(adjective, tough, severe, harsh)
1
grueling(adjective, tough, severe, difficult)
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APASmart Define. (2016). rigorous thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/rigorous/thesaurus/synonyms
ChicagoSmart Define. 2016. "rigorous thesaurus" https://smartdefine.org/rigorous/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2016, rigorous thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/rigorous/thesaurus/synonyms>.
MLASmart Define. "rigorous thesaurus" 26 February 2016. Web. 24 September 2026. <https://smartdefine.org/rigorous/thesaurus/synonyms>