891 entries under adjective topic. ×

7
rigorous(strong, hard, complete, tough)
7
standing pat(determined, resolute, obstinate, uncompromising)
7
unflagging(strong, tough, fit, solid)
7
vigorous(strong, tough, fit, solid)
6
bold(strong, vigorous, noble, resolute)
6
contrary(determined, resolute, persistent, obstinate)
6
direct(clear, plain, certain, definite)
6
forceful(clear, strong, sound, heavy)
6
grim(strong, hard, tough, severe)
6
harsh(mean, strong, hard, tough)
6
headstrong(hard, tough, rough, harsh)
6
hidebound(moderate, determined, resolute, cautious)
6
impervious(set, strong, hard, tough)
6
pat(solid, determined, usual, steady)
6
powerful(strong, sound, tough, fit)
6
recalcitrant(tough, persistent, obstinate, stubborn)
6
snug
6
stated(characteristic, certain, determined, usual)
6
trusty(good, close, strong, correct)
6
unbreakable(strong, hard, tough, severe)
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APASmart Define. (2016). firm thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/firm/thesaurus/synonyms
ChicagoSmart Define. 2016. "firm thesaurus" https://smartdefine.org/firm/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2016, firm thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/firm/thesaurus/synonyms>.
MLASmart Define. "firm thesaurus" 31 March 2016. Web. 25 September 2026. <https://smartdefine.org/firm/thesaurus/synonyms>