171 entries under tough topic. ×

1
unpermissive(adjective, hard, severe, rough)
1
unpleasant(adjective, severe, harsh, cruel)
1
unregenerate(adjective, hard, harsh, cruel)
1
unremitting(adjective, hard, harsh, cruel)
1
unrepenting(adjective, hard, harsh, cruel)
1
uphill battle(expression, adjective, rough, difficult)
1
uptight(adjective, severe, firm, harsh)
1
vengeful(adjective, harsh, grim, painful)
1
vindictive(adjective, hard, harsh, cruel)
1
wearing(adjective, rough, difficult, heavy)
1
wearying(adjective, rough, difficult, heavy)
0
bothersome(adjective, rough, difficult, heavy)
0
cold-blooded(adjective, harsh, grim, painful)
0
cold fish(expression, adjective, harsh, grim)
0
dense(adjective, strong, hard, sturdy)
0
ferric(adjective, strong, hard, sturdy)
0
ferrous(adjective, strong, hard, sturdy)
0
hard as nails(expression, adjective, idiom, severe)
0
herculean(adjective, rough, difficult, heavy)
0
insensible(adjective, strong, hard, sturdy)
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APASmart Define. (2016). rigorous thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/rigorous/thesaurus/synonyms
ChicagoSmart Define. 2016. "rigorous thesaurus" https://smartdefine.org/rigorous/thesaurus/synonyms (accessed September 27, 2026).
HarvardSmart Define 2016, rigorous thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/rigorous/thesaurus/synonyms>.
MLASmart Define. "rigorous thesaurus" 26 February 2016. Web. 27 September 2026. <https://smartdefine.org/rigorous/thesaurus/synonyms>