Synonyms|374Antonyms|68|Broader|6Narrower|0Related|45
3
enterprising(adjective, strong, moving, lively, active)
3
enthusiastic(adjective, determined, active, resolute, peppy)
3
fervent(adjective, tenacious)
3
hearty(adjective, strong, fit, healthy, well)
3
inexorable(adjective, resolute)
3
lively(adjective, strong, moving, active, vigorous)
3
obdurate(adjective, tenacious)
3
plodding(adjective, activity, strong, firm, determined)
3
plucky(adjective, resolute, tenacious)
3
set(adjective, resolute)
3
tough(adjective, strong, sound, fit, firm)
3
unbending(adjective, resolute)
3
unconquerable(adjective, perseverance)
3
undying(adjective, continuous)
3
unshakeable(adjective, resolute)
3
vital(adjective, strong, tough, fit, lively)
2
aggressive(adjective, strong, moving, lively, active)
2
ambitious
2
animated(adjective, strong, moving, lively, active)
2
ardent
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APASmart Define. (2015). indefatigable thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/indefatigable/thesaurus/synonyms
ChicagoSmart Define. 2015. "indefatigable thesaurus" https://smartdefine.org/indefatigable/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, indefatigable thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/indefatigable/thesaurus/synonyms>.
MLASmart Define. "indefatigable thesaurus" 10 April 2015. Web. 23 September 2026. <https://smartdefine.org/indefatigable/thesaurus/synonyms>