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Synonyms

definitely

American  
[def-uh-nit-lee] / ˈdɛf ə nɪt li /

adverb

  1. in a clear and definite manner; unambiguously.

  2. unequivocally; positively.

    Synonyms:
    certainly, absolutely

interjection

  1. (used to express complete agreement or strong affirmation).

    Are you starting your diet tomorrow? Definitely!

definitely British  
/ ˈdɛfɪnɪtlɪ /

adverb

  1. in a definite manner

  2. (sentence modifier) certainly

    he said he was coming, definitely

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

  1. unquestionably: used to confirm an assumption by a questioner

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Usage

What does definitely mean? Definitely is an adverb that usually means certainly or without a doubt. It also has this meaning when it’s used as a single-word response. Definitely is also sometimes used as an adverb to describe an action as clearly defined or precise. When definitely is used as a single word in response to a question or other statement, it is called an interjection or sentence substitute. When used this way, it is very similar to saying certainly or absolutely. Example: I will definitely be there tomorrow—I promise.

Related Words

See clearly.

Etymology

Origin of definitely

First recorded in 1575–85; definite + -ly

Compare meaning

How does definitely compare to similar and commonly confused words? Explore the most common comparisons:

Explanation

Use definitely to describe something you don’t have any doubt about. If you are certain you're going to see your friend's band play, you can assure him that you'll definitely be there. The adverb definitely is used to emphasize the certainty of whatever word it modifies. If you are sure you want apple pie, you could say you definitely want it. The base word definite can also mean "a certain limit," like the definite size a shelf must have to be. You wouldn't say "the carpenter definitely cuts the wood," to describe the exactness of the work; use precisely instead. AND, yes, definitely definitely has an e before the ly!

Keep Reading on Vocabulary.com

Vocabulary lists containing definitely

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“I definitely want somebody who appreciates what makes Adobe special and expands and extends that.”

From The Wall Street Journal • Apr. 20, 2026

“Rain should hold off today, even though we definitely need more rain.”

From Slate • Apr. 20, 2026

Near the end of the panel, an audience member asked a question some definitely had on their mind: Will “Seinfeld” ever get a reunion?

From Los Angeles Times • Apr. 19, 2026

"I'm not even sure I can remember exactly what I said to him, but I definitely can't take credit for the goal."

From BBC • Apr. 18, 2026

He had to concede that if asked, he would have most definitely said no.

From "The Very, Very Far North" by Dan Bar-el