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

Zombie series in these settings are still going to be pricey, and so AMC certainly has that to consider. —Paul Tassi, Forbes.com, 10 June 2025

Some historical context appears to be lost in this conversation because Sundowns certainly do not solely owe their success to their wealthy owner. —Simon Hughes, New York Times, 7 June 2025

With Quinn missing the cut in Phoenix, albeit certainly qualified, there is little room for shifting of the staff, although Kasib Powell this past season moved on from his role as a Heat developmental assistant to an assistant role with the expansion WNBA Golden State Valkyries. —Ira Winderman, Sun Sentinel, 7 June 2025

Paella Valenciana Paella is perhaps the most famous Spanish dish of all, and certainly one of the most abused. —Jon Yeomans, CNN Money, 7 June 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing certainly

• certainly not

Rhymes for certainly

• uncertainly

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