255 entries under adjective topic. ×

35
tireless(strong, continue, firm, difficult)
27
unflagging(strong, tough, continue, fit)
25
persistent(strong, firm, determined, steady)
21
untiring(strong, continue, lively, determined)
20
persevering(strong, firm, difficult, determined)
19
dogged(strong, firm, determined, steady)
19
steadfast(resolute, persevering, tenacious, untiring)
18
determined(strong, firm, steady, resolute)
17
diligent(activity, resolute, persevering, tenacious)
17
energetic(determined, active, full, forceful)
16
unfaltering(strong, firm, determined, steady)
16
unwavering(set, strong, firm, determined)
15
resolute(set, strong, firm, determined)
15
sedulous(activity, untiring)
14
assiduous(activity, untiring)
14
tenacious(strong, tough, fit, firm)
13
unwearying
12
unfailing(set, strong, continue, firm)
12
inexhaustible(strong, continue, firm, energetic)
12
unwearied(activity, strong, continue, firm)
<1234510>
11 years ago|10k views|share |citing 
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>