certainly

adverb

cer·​tain·​ly ˈsər-tᵊn-lē 

1

: in a manner that is certain : with certainty

2

: it is certain that : assuredly

Synonyms of certainly

• definitely
• surely
• sure
• clearly
• probably
• really

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

Some months back, the Graphene team revealed the first device in its Moto collaboration would be priced above Pixels, and that certainly checks out. — Ryan Whitwam, ArsTechnica, 5 Nov. 2026

These days, Sand’s quarter-zips and button-down shirts are a bit more gubernatorial than what’s seen on the runways in Paris and Milan—his midwestern flair is certainly miles from the likes of Haider Ackermann’s Tom Ford. — Alexandra Hildreth, Vogue, 5 Nov. 2026

The Spurs certainly needed their All-Star in the final minutes. — ABC News, 5 Nov. 2026

There's certainly no shortage of visual drama, but whether all these design elements come together into something cohesive is another matter. — New Atlas, 5 Nov. 2026

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