1
hardboiled(adjective, serious, resolute, persistent, unwavering)
1
hell-bent
1
hubristic
1
icy(adjective, bold, unconcerned, brave, steadfast)
1
in the bag(expression, adjective, idiom, certain, limited)
1
incessant(adjective, strong, firm, determined, steady)
1
inexcitable
1
inexorable(adjective, intense, resolute, persistent, rigid)
1
intense(adjective, firm, solid, deliberate, determined)
1
invariant
1
inveterate(adjective, certain, limited, definite, inflexible)
1
invincible
1
level(adjective, certain, limited, definite, inflexible)
1
limited(adjective, certain, definite, inflexible, restricted)
1
mean business(expression, adjective, intense, deliberate, determined)
1
meaning business(adjective, steadfast)
1
mulish(adjective, steadfast)
1
narrow(adjective, certain, limited, definite, inflexible)
1
nerveless
1
never-tiring
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APASmart Define. (2015). unfaltering thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/unfaltering/thesaurus/synonyms
ChicagoSmart Define. 2015. "unfaltering thesaurus" https://smartdefine.org/unfaltering/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2015, unfaltering thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/unfaltering/thesaurus/synonyms>.
MLASmart Define. "unfaltering thesaurus" 10 April 2015. Web. 24 September 2026. <https://smartdefine.org/unfaltering/thesaurus/synonyms>