48 entries under permanent topic. ×

7
irreversible(adjective, fixed, even, rigid, inflexible)
5
perennial(adjective, stable, constant, stability, enduring)
5
unending(adjective, persistent, constant, continuous, endless)
5
unmodifiable(adjective, set, secure, steady, fixed)
4
set(adjective, calm, strong, secure, firm)
4
timeless(adjective, lasting, everlasting, unending)
4
uncompromising(adjective, hard, secure, rough, firm)
3
ageless(adjective, fixed, lasting, unchanging)
2
ceaseless(adjective, persistent, constant, continuous, endless)
2
continuous(adjective, persistent, constant, endless, indefinite)
2
intransigent(steady, fixed, impassive, inflexible, stubborn)
2
perdurable(calm, strong, solid, substantial, constant)
2
relentless(adjective, set, strong, hard, firm)
2
unfading(stable, fixed, constant, enduring, lasting)
2
unremitting(adjective, persistent, constant, continuous, endless)
1
continued(lasting, everlasting, unending, undying)
1
dateless(lasting, everlasting, unending, undying)
1
fated(adjective, fixed, even, rigid, inflexible)
1
forever(stable, constant, enduring, lasting)
1
immemorial(lasting, everlasting, unending, undying)
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APASmart Define. (2015). immutable thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/immutable/thesaurus/synonyms
ChicagoSmart Define. 2015. "immutable thesaurus" https://smartdefine.org/immutable/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, immutable thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/immutable/thesaurus/synonyms>.
MLASmart Define. "immutable thesaurus" 10 April 2015. Web. 22 September 2026. <https://smartdefine.org/immutable/thesaurus/synonyms>