2
large(adjective, big, grand, huge, broad)
2
lifelong(adjective, durable)
2
livelong(adjective, durable)
2
long-life(adjective, durable)
2
loose(dull, wordy, prolix, verbose, diffuseness)
2
no end of(verb, expression, idiom, phrasal verb, length)
2
oblong(protracted, ovated)
2
outstretched(adjective, great, deep, high, remote)
2
perennial(adjective, durable)
2
persistent
2
ponderous(adjective, wordy)
2
rangy(adjective, great, deep, high, remote)
2
redundant(dull, loose, rambling, wordy, prolix)
2
slow(adjective, boring, tedious, late, rambling)
2
tiresome(adjective, difficult, slow, tedious, long)
2
unending(adjective, slow, boring, tedious, late)
2
wandering(adjective, wordy)
2
wide(adjective, big, large, grand, huge)
2
without end(expression, slow, boring, tedious, late)
1
across the board(expression, idiom, big, huge, major)
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APASmart Define. (2016). lengthy thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/lengthy/thesaurus/synonyms
ChicagoSmart Define. 2016. "lengthy thesaurus" https://smartdefine.org/lengthy/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, lengthy thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/lengthy/thesaurus/synonyms>.
MLASmart Define. "lengthy thesaurus" 26 February 2016. Web. 23 September 2026. <https://smartdefine.org/lengthy/thesaurus/synonyms>