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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While Spencer Jones is still a work in progress defensively in center, Grisham certainly shouldn’t be patrolling the position for the Yankees moving forward. — Gary Phillips, New York Daily News, 9 Oct. 2026 Next-level attentiveness from friendly staff certainly helps. — Condé Nast, Condé Nast Traveler, 8 Oct. 2026 When a hurricane comes barreling through Florida, there certainly will be winners and losers. — James Coffin, The Orlando Sentinel, 8 Oct. 2026 If there is any place that would be off-limits to AI, the control room of a nuclear power plant certainly sounds like one. — Andrew Moseman, IEEE Spectrum, 8 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 14 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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