Synonyms

confirm

American

[kuhn-furm] / kənˈfɜrm /

verb (used with object)

to establish the truth, accuracy, validity, or genuineness of; corroborate; verify.

This report confirms my suspicions.

Synonyms:

validate, authenticate, substantiate, prove

Antonyms:

disprove
to acknowledge with definite assurance.

Did the hotel confirm our room reservation?
to make valid or binding by some formal or legal act; sanction; ratify.

to confirm a treaty;
to confirm her appointment to the Supreme Court.

Antonyms:

invalidate
to make firm or more firm; add strength to; settle or establish firmly.

Their support confirmed my determination to run for mayor.

Synonyms:

fix

Antonyms:

shake
to strengthen (a person) in habit, resolution, opinion, etc..

The accident confirmed him in his fear of driving.
to administer the religious rite of confirmation to.

confirm British

/ kənˈfɜːm /

verb

(may take a clause as object) to prove to be true or valid; corroborate; verify
(may take a clause as object) to assert for a second or further time, so as to make more definite

he confirmed that he would appear in court
to strengthen or make more firm

his story confirmed my doubts
to make valid by a formal act or agreement; ratify
to administer the rite of confirmation to

"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

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Inflected Forms

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Conjugated Forms

Present

Past

Future

Etymology

Origin of confirm

First recorded in 1250–1300; from Latin confirmāre “to strengthen, confirm” ( see con-, firm ¹); replacing Middle English confermen, from Old French, from Latin, as above

Explanation

When you need to make sure before you leave that you have a reservation, you often call ahead to confirm, that is, to make sure that your tickets or space are set aside for you. The firm in confirm should give you a clue as to the word's meaning: to shore up or verify something. When you make sure something is set, or firm, you confirm it. The word comes from the Latin con- "together, altogether," and firmāre "make firm," so confirm originally meant roughly "to make (something) altogether firm."

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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.

See Examples For:

confirm confirms confirmed confirming

If future clinical trials confirm its safety and effectiveness, a familiar everyday product could become an unexpected addition to the medical toolkit against dangerous oral infections and cancers.

From Science Daily ● Nov. 11, 2026

I wasn’t part of those surveys, but the numbers confirm what I know from regrettable experience, as I describe in a new book.

From Slate ● Nov. 11, 2026

Huge cheers greeted his number being shown to confirm he was being replaced, which then turned to boos when he reached the dugout.

From BBC ● Nov. 9, 2026

The consumer-price index for October, due out Tuesday morning, is expected to confirm inflation remained still stubbornly high.

From MarketWatch ● Nov. 9, 2026

Supreme Court issued a ruling that seemed to confirm that optimism.

From "The Best of Enemies" by Osha Gray Davidson

The Public Accounts Committee report also confirms what has happened since Mountbatten-Windsor's departure from Royal Lodge.

From BBC ● Nov. 6, 2026

Independent research confirms that trades on some economic outcomes outperform the Wall Street consensus.

From The Wall Street Journal ● Oct. 27, 2026

Extensive research confirms the axiom that a sense of civic duty is the strongest predictor of whether someone will vote.

From Salon ● Oct. 20, 2026

If further research confirms its safety and effectiveness, the technology could reduce the need for more invasive procedures while making advanced nerve stimulation treatments easier to deliver.

From Science Daily ● Oct. 11, 2026

If he confirms, are you okay for convening at 5 tomorrow?

From "Saints and Misfits" by S.K. Ali

Recent inflation data confirmed that price pressures outside of energy have started to ratchet higher once again.

From MarketWatch ● Nov. 11, 2026

Local press went wild describing details of Bertulazzi's escape from his residence in the capital, but authorities have not confirmed the veracity of any of the reports.

From Barron's ● Nov. 11, 2026

Most local authorities contacted by BBC Scotland said schools were operating as normal but some confirmed pupils had been evacuated.

From BBC ● Nov. 11, 2026

Their analysis confirmed that the proteins were genuinely ancient rather than the result of contamination from modern sources.

From Science Daily ● Nov. 11, 2026

“The biodrones have confirmed the atmosphere has sufficient oxygen.”

From "The Last Cuentista" by Donna Barba Higuera

Harrington eventually told Brooks: "I'm confirming the on-field decision of no red card. There's a lack of speed going into the challenge and he's stepping into the tackle. Confirming a reckless challenge."

From BBC ● Nov. 7, 2026

“And that became part of the story,” Melvin said, before confirming that he had apologized for the spilled chocolate when it had happened.

From Los Angeles Times ● Nov. 6, 2026

The analysis produced a 98 to 99 percent match with P. imbricornus, confirming the identity of the beetle responsible for the root damage.

From Science Daily ● Nov. 6, 2026

The FBI accused North Korea of being behind the attack on Saturday, confirming earlier suspicions from private investigators and analysts that a Pyongyang-affiliated group called TraderTraitor was behind the hack.

From Barron's ● Nov. 1, 2026

After several minutes, when I hear an exchange between Plutarch and the pilot confirming that the airspace is clear, I begin to relax a little.

From "Mockingjay" by Suzanne Collins

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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023