222 entries under tough topic. ×

2
active(adjective, strong, sound, fit)
2
cantankerous(adjective, persistent, obstinate, stubborn)
2
cussed(adjective, persistent, obstinate, stubborn)
2
dour(adjective, severe, harsh, cruel)
2
hard-boiled(adjective, mean, strong, hard)
2
hard-core(adjective, close, strong, hard)
2
hard-hearted(adjective, mean, hard, harsh)
2
hard-shell(adjective, strong, hard, severe)
2
long-lasting(adjective, familiar, sturdy, established)
2
opinionated(adjective, determined, unreasonable, fixed)
2
persisting(adjective, strong, determined, steady)
2
perverse(adjective, mean, hard, determined)
2
puritanical(adjective, severe, harsh, rigid)
2
rebellious(adjective, unreasonable, inflexible, obstinate)
2
rough(adjective, strong, hard, severe)
2
steel(verb, adjective, close, set, fix)
1
able(adjective, strong, sound, easy)
1
all right(expression, strong, fit, fresh)
1
astringent(adjective, strong, hard, severe)
1
athletic(strong, sound, fit, solid)
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APASmart Define. (2016). firm thesaurus. Retrieved September 29, 2026, from https://smartdefine.org/firm/thesaurus/synonyms
ChicagoSmart Define. 2016. "firm thesaurus" https://smartdefine.org/firm/thesaurus/synonyms (accessed September 29, 2026).
HarvardSmart Define 2016, firm thesaurus, Smart Define, viewed 29 September, 2026, <https://smartdefine.org/firm/thesaurus/synonyms>.
MLASmart Define. "firm thesaurus" 31 March 2016. Web. 29 September 2026. <https://smartdefine.org/firm/thesaurus/synonyms>