4
prolonged(adjective, persistent, lasting, durable, remaining)
3
incessant(adjective, permanent, durable, recurrent, perpetual)
3
long(adjective, durable)
2
abiding(adjective, fixed, persistent, hardened, lasting)
2
continual(adjective, fixed, persistent, continuous, lasting)
2
continuous(adjective, fixed, persistent, lasting, continuing)
2
evergreen
2
fixed(verb, persistent, continuous, hardened, lasting)
2
for life(expression, adjective, idiom, lasting, longstanding)
2
indissoluble(adjective, permanent, long-term)
2
interminable(adjective, durable)
2
lengthy(adjective, durable)
2
life
2
long-life(adjective, durable)
2
long-standing(adjective, persistent, continuous, hardened, lasting)
2
settled(verb, persistent, continuous, hardened, lasting)
2
strong
2
undying(adjective, permanent, recurrent, perpetual, long-term)
1
protracted(adjective, persistent, continuous, lasting, continuing)
1
all-night
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APASmart Define. (2015). lifelong thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/lifelong/thesaurus/synonyms
ChicagoSmart Define. 2015. "lifelong thesaurus" https://smartdefine.org/lifelong/thesaurus/synonyms (accessed September 27, 2026).
HarvardSmart Define 2015, lifelong thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/lifelong/thesaurus/synonyms>.
MLASmart Define. "lifelong thesaurus" 14 April 2015. Web. 27 September 2026. <https://smartdefine.org/lifelong/thesaurus/synonyms>