255 entries under adjective topic. ×

11
industrious(activity, strong, difficult, energetic)
11
staunch(strong, tough, fit, firm)
11
steady(strong, firm, determined, resolute)
11
vigorous(strong, sound, tough, fit)
10
loyal
10
stubborn(resolute, tenacious)
10
unswerving(set, strong, firm, determined)
9
constant(strong, firm, determined, steady)
9
indomitable(strong, firm, determined, steady)
9
pertinacious(strong, firm, determined, steady)
8
firm(strong, tough, fit, solid)
8
patient(noun, strong, firm, determined)
8
relentless(resolute, untiring)
8
resolved
8
unflinching(set, strong, firm, determined)
8
unremitting(strong, firm, determined, steady)
7
painstaking(activity, untiring)
7
strenuous(strong, moving, difficult, energetic)
7
weariless(continue, tired, tireless)
6
bold(resolute, tenacious)
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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>