217 entries under adjective topic. ×

22
immutable(calm, strong, hard, secure)
22
steady(calm, strong, secure, strain)
21
durable(strain, firmness, stability, labour)
19
fast(strain, firmness, labour, hardiness)
19
long-standing(strain, firmness, labour, hardiness)
19
perpetual(strain, steady, stable, regular)
19
refractory(hard, strain, rough, harsh)
19
stabile(calm, strong, secure, strain)
19
stationary(strain, firmness, labour, hardiness)
19
stout(strain, firmness, labour, hardiness)
19
substantial(strain, firmness, labour, hardiness)
18
sustained(strain, firmness, persistent, continuous)
18
well-balanced(strain, firmness, even, labour)
17
unchanging(severe, firm, harsh, solid)
13
changeless
13
inflexible(set, strong, hard, secure)
11
inalterable(inflexible, changeable, flexible)
11
irrevocable(change, set, fixed, necessary)
10
irreversible(change, complete, fixed, even)
9
certain(definite, fixed, distinct, rigid)
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APASmart Define. (2015). unalterable thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/unalterable/thesaurus/synonyms
ChicagoSmart Define. 2015. "unalterable thesaurus" https://smartdefine.org/unalterable/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2015, unalterable thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/unalterable/thesaurus/synonyms>.
MLASmart Define. "unalterable thesaurus" 13 April 2015. Web. 24 September 2026. <https://smartdefine.org/unalterable/thesaurus/synonyms>