1
unequivocal(clear, certain, valid, unquestionable, undisputable)
1
unfaultable
1
unimpeachable(adjective, perfect, precise, flawless, faultless)
1
unmixed
1
unspotted
1
untainted
1
valid(clear, complete, certain, sure, unquestionable)
0
abiding(certain, reliable, trustworthy, unquestionable, undisputable)
0
admittedly
0
alright
0
an
0
assault
0
assiduous
0
assurance
0
assuredly
0
attack
0
bottomless
0
bound to be(expression, idiom, certain, unquestionable, undisputable)
0
boundless
0
break
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APASmart Define. (2015). infallible thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/infallible/thesaurus/synonyms
ChicagoSmart Define. 2015. "infallible thesaurus" https://smartdefine.org/infallible/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2015, infallible thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/infallible/thesaurus/synonyms>.
MLASmart Define. "infallible thesaurus" 10 April 2015. Web. 24 September 2026. <https://smartdefine.org/infallible/thesaurus/synonyms>