75 entries under certain topic. ×

21
sure(adjective, clear, complete, reliable)
19
reliable(adjective, clear, certainty, flawless)
17
unfailing(adjective, flawless, reliable, trustworthy)
17
certain(adjective, reliable, valid, dependable)
12
unerring(adjective, clear, precise, sure)
10
dependable(adjective, flawless, reliable, trustworthy)
7
inerrant(adjective, complete, sure, valid)
7
secure(verb, adjective)
6
absolute
6
accurate(adjective, perfect, precise, flawless)
5
positive(adjective, clear, valid, dependable)
4
necessary(adjective, inevitable)
4
sure-fire(adjective, informal, flawless, dependable)
3
bound(certainty, unquestionable, undisputable)
3
incontrovertible(adjective, clear, valid, dependable)
3
surefire(adjective, reliable, trustworthy, dependable)
3
unquestionable(adjective, dependable, undisputable, unerring)
2
assured(unquestionable, undisputable, inevitable)
2
constant(reliable, trustworthy, unquestionable, undisputable)
2
definite(adjective, clear, valid, unquestionable)
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APASmart Define. (2015). infallible thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/infallible/thesaurus/synonyms
ChicagoSmart Define. 2015. "infallible thesaurus" https://smartdefine.org/infallible/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, infallible thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/infallible/thesaurus/synonyms>.
MLASmart Define. "infallible thesaurus" 10 April 2015. Web. 23 September 2026. <https://smartdefine.org/infallible/thesaurus/synonyms>