77 entries under certainly topic. ×

8
obviously(adverb, absolutely, positively, clearly)
8
without doubt(expression, idiom, adverb, absolutely, exactly)
7
incontrovertibly(adverb, positively, precisely, clearly)
6
actually(adverb, well, absolutely, very, really)
6
exactly(adverb, good, fine, true, sure)
6
plainly
5
decisively(adverb, absolutely, really, exactly, positively)
5
incontestably
5
precisely(good, fine, well, absolutely, exactly)
5
unmistakably(adverb, absolutely, really, positively)
5
yes(adverb, sure, just, exactly, positively)
4
all right(expression, adjective, idiom, adverb, good)
4
beyond doubt(expression, idiom, adverb, absolutely, very)
4
irrefutably(adverb, absolutely, clearly, plainly)
4
sure enough(expression, idiom, adverb, really, exactly)
3
honestly(adverb, well, absolutely, really, exactly)
3
okay(adjective, adverb, good, correct, fine)
3
steadfastly
3
sure thing(expression, idiom, absolutely, very, exactly)
3
veritably(adverb, absolutely, very, really, exactly)
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APASmart Define. (2015). surely thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/surely/thesaurus/synonyms
ChicagoSmart Define. 2015. "surely thesaurus" https://smartdefine.org/surely/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, surely thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/surely/thesaurus/synonyms>.
MLASmart Define. "surely thesaurus" 14 April 2015. Web. 21 September 2026. <https://smartdefine.org/surely/thesaurus/synonyms>