certainly

adverb

cer·​tain·​ly ˈsər-tᵊn-lē How to pronounce certainly (audio)
Synonyms of certainly
1
: in a manner that is certain : with certainty
2
: it is certain that : assuredly

Synonyms of certainly

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Examples of certainly in a Sentence

It will certainly rain tomorrow. This year's festival was certainly much better than last year's. I'm certainly going to try. The new version is most certainly easier to use. The snake that bit her was almost certainly poisonous.
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Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Between Skubal, Glasnow, Snell and 2025 World Series MVP Yoshinobu Yamamoto, the Dodgers almost certainly wouldn’t need Ohtani until a best-of-seven series. — Fabian Ardaya, New York Times, 2 Aug. 2026 The gorpcore girls and athleisure crowd would almost certainly disagree, however, and make a convincing case for wearing one with Salomon sneakers, sporty layers, and an enormous nylon jacket. — Georgia Brown, Glamour, 2 Aug. 2026 But the New York Mets, in the largest market in the major leagues, certainly could. — Bill Shaikin, Los Angeles Times, 2 Aug. 2026 Femi is clearly the next person in line to get a title shot and his eyes will certainly be on the outcome of the World Heavyweight Championship match between Roman Reigns and Seth Rollins on Night 2 of SummerSlam. — Ryan Gaydos, FOXNews.com, 2 Aug. 2026 See All Example Sentences for certainly

Word History

First Known Use

14th century, in the meaning defined at sense 1

Time Traveler
The first known use of certainly was in the 14th century

Phrases Containing certainly

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certain
certainly
certainly not
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Cite this Entry

“Certainly.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/certainly. Accessed 5 Aug. 2026.

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Kids Definition

certainly

adverb
cer·​tain·​ly ˈsərt-ᵊn-lē How to pronounce certainly (audio)
1
: in a manner that is certain : for certain
the only event of which anything is certainly known
2
: without doubt : surely
certainly you can do it

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