1
for keeps(expression, stable, constant, enduring, lasting)
1
forever and a day(expression, idiom, stable, constant, lasting)
1
frozen
1
green
1
immemorial(vast, lasting, permanent, everlasting, unending)
1
immortalization
1
immutable(adjective, stable, fixed, constant, enduring)
1
impregnable
1
imputrescible
1
in for the long haul(expression, idiom, stable, constant, lasting)
1
incessant(adjective, perpetuity)
1
indeciduous
1
indefinite(lasting, permanent, everlasting, unending, undying)
1
ineffaceable
1
inexpugnable
1
invariable(stable, fixed, constant, enduring, lasting)
1
invincible
1
invulnerable
1
irreducible
1
irrefragable
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APASmart Define. (2016). imperishable thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/imperishable/thesaurus/synonyms
ChicagoSmart Define. 2016. "imperishable thesaurus" https://smartdefine.org/imperishable/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, imperishable thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/imperishable/thesaurus/synonyms>.
MLASmart Define. "imperishable thesaurus" 29 March 2016. Web. 21 September 2026. <https://smartdefine.org/imperishable/thesaurus/synonyms>