1
keen
1
level(adjective, continuous)
1
lusty(adjective, strong, sound, tough, fit)
1
meticulous
1
mettlesome
1
monolithic(adjective, continuous)
1
mulish
1
muscular(strong, fit, healthy, well, robust)
1
never-ending
1
never-tiring
1
never idle
1
never tiring(expression, idiom, perseverance)
1
nonstop(adjective, continuous)
1
nose to grindstone(adjective, untiring)
1
perennial(adjective, continuous)
1
permanent
1
pigheaded
1
potent(adjective, strong, tough, fit, lively)
1
pounding
1
powerful(adjective, strong, sound, tough, fit)
<1678910>
11 years ago|10k views|share |citing 
APASmart Define. (2015). indefatigable thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/indefatigable/thesaurus/synonyms
ChicagoSmart Define. 2015. "indefatigable thesaurus" https://smartdefine.org/indefatigable/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2015, indefatigable thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/indefatigable/thesaurus/synonyms>.
MLASmart Define. "indefatigable thesaurus" 10 April 2015. Web. 24 September 2026. <https://smartdefine.org/indefatigable/thesaurus/synonyms>