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.
Putin’s expansionist Russian strategy seems eerily like Adolf Hitler’s advances across Europe and certainly reminiscent of Soviet Russia building an Iron Curtain around Eastern European nations after World War II. — Bob Kustra, Chicago Tribune, 22 Oct. 2026 There was certainly a sky-blue wave in Atlanta on Wednesday night. — Don Riddell, CNN Money, 22 Oct. 2026 Boise State head coach Spencer Danielson said before the game that some of the team’s younger receivers would have to step up, and Favors certainly didn’t disappoint. — Shaun Goodwin, Idaho Statesman, 22 Oct. 2026 But the scenes — his body covered in medical equipment, his limbs not moving, his teammates down on a knee — certainly created cause for concern. — Daniel Flick, AJC.com, 22 Oct. 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 27 Oct. 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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