10
rigid(adjective, set, hard, regular, fixed)
10
unyielding(adjective, strong, hard, steady, resolute)
9
inexorable(adjective, hard, resolute, rigid, inflexible)
9
lasting(adjective, calm, strong, solid, steady)
9
unvarying(adjective, calm, clear, strong, secure)
9
unwavering(adjective, calm, strong, secure, flat)
8
irreversible(adjective, constant, steadfast)
8
inalterable(adjective, certain, limited, definite, fixed)
8
irrevocable(adjective, certain, unquestionable, undisputable, irreversible)
8
resolved(adjective, strong, flat, certain, determined)
8
sure(adjective, calm, strong, secure, flat)
8
unbending(adjective, strong, flat, certain, determined)
8
uncompromising(adjective, complete, secure, certain, true)
8
undeviating(adjective, strong, flat, certain, determined)
7
adamant(adjective, strong, definite, rigid, inflexible)
7
enduring(adjective, calm, strong, secure, flat)
7
hard(adjective, resolute, rigid, inflexible, strict)
7
set(adjective, calm, strong, secure, flat)
7
staunch(adjective, calm, strong, secure, flat)
7
stiff(adjective, set, hard, resolute, rigid)
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APASmart Define. (2015). unchangeable thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/unchangeable/thesaurus/synonyms
ChicagoSmart Define. 2015. "unchangeable thesaurus" https://smartdefine.org/unchangeable/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, unchangeable thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/unchangeable/thesaurus/synonyms>.
MLASmart Define. "unchangeable thesaurus" 3 August 2015. Web. 22 September 2026. <https://smartdefine.org/unchangeable/thesaurus/synonyms>