2
unbreakable(adjective, strong, tough)
2
unceasing(continuous, lasting, permanent, everlasting, perpetual)
2
undying(adjective, continuous, enduring, lasting, permanent)
2
unending(absolute, endless, enduring, lasting, immense)
2
unfading(stable, constant, enduring, lasting, permanent)
2
unremitting(continuous, lasting, permanent, everlasting, unending)
2
without end(expression, absolute, endless, lasting, immense)
1
age-long
1
anchored(calm, strong, solid, steady, substantial)
1
ancient
1
antique
1
balanced(calm, strong, solid, steady, substantial)
1
brick-wall(calm, strong, solid, steady, substantial)
1
calm(strong, solid, steady, substantial, even)
1
ceaseless
1
coeternal
1
continued(continuous, lasting, permanent, everlasting, uninterrupted)
1
deep-rooted(calm, strong, solid, steady, substantial)
1
diuturnal
1
endure
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APASmart Define. (2016). perdurable thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/perdurable/thesaurus/synonyms
ChicagoSmart Define. 2016. "perdurable thesaurus" https://smartdefine.org/perdurable/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, perdurable thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/perdurable/thesaurus/synonyms>.
MLASmart Define. "perdurable thesaurus" 3 March 2016. Web. 21 September 2026. <https://smartdefine.org/perdurable/thesaurus/synonyms>