6
overlong(adjective, great, excite, slow, high)
6
tedious(adjective, dull, slow, boring, late)
6
time-consuming(adjective, dull, moderate, low, stiff)
5
chronic(adjective, continue, persistent, constant, lasting)
5
maintained(verb, adjective, constant, continued)
5
slow(adjective, boring, tedious, late, rambling)
4
delayed(verb, adjective, dull, low, slow)
4
elongate(adjective, great, deep, high, remote)
4
endless(adjective, constant, huge, immense, massive)
4
lifelong(adjective, persistent, lasting, durable, remaining)
4
persistent(adjective, continue, constant, lasting, protracted)
4
prolix(adjective, slow, boring, tedious, late)
4
spun out(verb, expression, adjective, phrasal verb, great)
3
abiding(adjective, persistent, lasting, remaining, continued)
3
continuous(adjective, persistent, constant, lasting, unremitting)
3
dull(adjective, slow, tedious, late, protracted)
3
enduring(adjective, great, deep, high, persistent)
3
everlasting(adjective, durable)
3
perennial(adjective, persistent, lasting, durable, remaining)
3
perpetual(adjective, steady, stable, regular, constant)
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APASmart Define. (2015). prolonged thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/prolonged/thesaurus/synonyms
ChicagoSmart Define. 2015. "prolonged thesaurus" https://smartdefine.org/prolonged/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, prolonged thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/prolonged/thesaurus/synonyms>.
MLASmart Define. "prolonged thesaurus" 13 April 2015. Web. 22 September 2026. <https://smartdefine.org/prolonged/thesaurus/synonyms>