3
perverse(adjective, mean, hard, tough, firm)
3
pigheaded(adjective, mean, hard, tough, firm)
3
resolved(adjective, determined, resolute, uncompromising, unshakeable)
3
retaliatory(adjective, mean, hateful, malicious, spiteful)
3
rigorous(adjective, strong, hard, tough, harsh)
3
rock-ribbed(adjective, determined, resolute, uncompromising, unshakeable)
3
strong-willed(adjective, determined, resolute, uncompromising, unshakeable)
3
unmoved
3
unshakeable(adjective, determined, resolute, uncompromising)
2
barbaric(adjective, animal, mean, violent, cruel)
2
bitter(adjective, strong, hard, tough, severe)
2
bold(adjective, resolute)
2
constant(adjective, resolute)
2
decided(adjective, resolute)
2
decisive(adjective, resolute)
2
dedicated(adjective, resolute)
2
diligent(adjective, resolute)
2
fell(adjective, animal, mean, violent, cruel)
2
fierce(adjective, animal, mean, hard, tough)
2
fixed(adjective, mean, hard, tough, firm)
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APASmart Define. (2016). implacable thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/implacable/thesaurus/synonyms
ChicagoSmart Define. 2016. "implacable thesaurus" https://smartdefine.org/implacable/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, implacable thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/implacable/thesaurus/synonyms>.
MLASmart Define. "implacable thesaurus" 24 March 2016. Web. 20 September 2026. <https://smartdefine.org/implacable/thesaurus/synonyms>