30
settled(adjective, strain, firmness, labour, hardiness)
28
fast(adjective, strain, firmness, labour, hardiness)
28
steady(adjective, calm, strong, secure, strain)
25
long-standing(adjective, continue, strain, firmness, labour)
22
immutable(adjective, calm, strong, secure, firm)
21
staying(adjective, strain, firmness, labour, hardiness)
21
unchanging(adjective, firm, steady, stable, regular)
20
abiding(adjective, calm, strong, secure, tough)
20
impregnable(adjective, strain, firmness, labour, hardiness)
20
rigid(adjective, strain, firmness, labour, hardiness)
20
stabile(adjective, calm, strong, secure, strain)
20
stout(adjective, strain, firmness, labour, hardiness)
20
substantial(adjective, strain, firmness, labour, hardiness)
20
sustained(adjective, strain, firmness, persistent, continuous)
19
changeless(adjective, stable, fixed, constant, enduring)
19
quiescent(adjective, strain, firmness, labour, hardiness)
19
resistant(adjective, strain, firmness, labour, hardiness)
19
tight(adjective, strain, firmness, labour, hardiness)
18
unyielding(adjective, strain, firmness, labour, hardiness)
17
unchangeable(adjective, calm, strong, solid, substantial)
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APASmart Define. (2016). permanent thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/permanent/thesaurus/synonyms
ChicagoSmart Define. 2016. "permanent thesaurus" https://smartdefine.org/permanent/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, permanent thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/permanent/thesaurus/synonyms>.
MLASmart Define. "permanent thesaurus" 26 February 2016. Web. 20 September 2026. <https://smartdefine.org/permanent/thesaurus/synonyms>