120 entries under true topic. ×

83
sure(adjective, good, set, clear, understanding)
47
positive(adjective, good, set, clear, strong)
44
definite(adjective, good, clear, strong, complete)
35
unquestionable(adjective, clear, correct, flat, honest)
34
indisputable(adjective, certain, ideal, unequivocal)
32
absolute(adjective, clear, strong, complete, correct)
27
undeniable(adjective, certain, definite, absolute)
24
incontestable(adjective, certain, ideal, unequivocal)
24
incontrovertible(adjective, certain, ideal, valid)
23
indubitable(adjective, clear, certain, real)
22
specific(adjective, clear, correct, plain, exact)
19
determined(adjective, good, strong, easy, firm)
17
dependable(adjective, good, clear, strong, sound)
17
irrefutable(adjective, certain, definite, sure)
17
reliable(adjective, clear, strong, sound, easy)
17
particular(adjective, correct, exact, extraordinary, superior)
15
firm(noun, adjective, good, change, clear)
15
secure(verb, adjective, clear, sound, firm)
15
unfailing(adjective, strong, reliable, trustworthy)
14
authentic(adjective, correct, honest, straight)
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APASmart Define. (2016). certain thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/certain/thesaurus/synonyms
ChicagoSmart Define. 2016. "certain thesaurus" https://smartdefine.org/certain/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, certain thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/certain/thesaurus/synonyms>.
MLASmart Define. "certain thesaurus" 31 March 2016. Web. 20 September 2026. <https://smartdefine.org/certain/thesaurus/synonyms>