certainly

adverb

cer·​tain·​ly ˈsər-tᵊn-lē 

1

: in a manner that is certain : with certainty

2

: it is certain that : assuredly

Synonyms

• all right
• alright
• assuredly
• clearly
• definitely
• doubtless
• easily
• forsooth
• hands down
• inarguably
• incontestably
• incontrovertibly
• indeed
• indisputably
• plainly
• really
• so
• sure
• surely
• truly
• unarguably
• undeniably
• undoubtedly
• unquestionably

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.

Recent Examples on the Web

And while that was certainly true this year, the real winners in a lot of ways were the new additions to the guitar amplifier world. —Josh Chesler, SPIN, 29 Jan. 2025

But his educational background in politics and Hellenic studies is certainly out of the ordinary. —Michael S. Lubell, Scientific American, 29 Jan. 2025

Dermatologists say there is certainly merit to the idea that toxic relationships take a toll on your skin, as well as your overall health, and thereby contribute to acne. —Charles Trepany, USA TODAY, 29 Jan. 2025

That’s certainly what some felt about Obama-era legislation called the Stop Online Piracy Act (or SOPA), which lawmakers quickly walked back after facing a really furious onslaught by the U.S. tech industry. —Jill Goldsmith, Deadline, 29 Jan. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing certainly

• certainly not

Kids Definition

certainly

adverb

cer·​tain·​ly ˈsərt-ᵊn-lē 

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