confirm

American  

[kuhn-furm] / kənˈfɜrm /

verb (used with object)

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

   This report confirms my suspicions.

   Synonyms:

   validate, authenticate, substantiate, prove

   Antonyms:

   disprove

2. to acknowledge with definite assurance.

   Did the hotel confirm our room reservation?

3. 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

4. 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

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

   The accident confirmed him in his fear of driving.

6. to administer the religious rite of confirmation to.

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confirm British  

/ kənˈfɜːm /

verb

1. (may take a clause as object) to prove to be true or valid; corroborate; verify

2. (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

3. to strengthen or make more firm

   his story confirmed my doubts

4. to make valid by a formal act or agreement; ratify

5. to administer the rite of confirmation to

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Other Word Forms

• confirmability noun
• confirmable adjective
• confirmatory adjective
• confirmer noun
• confirmingly adverb
• nonconfirming adjective
• preconfirm verb (used with object)
• reconfirm verb (used with object)
• unconfirm verb (used with object)
• unconfirmability noun

Etymology

Origin of confirm

First recorded in 1250–1300; from Latin confirmāre “to strengthen, confirm” ( 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."

Example Sentences

Augusta National opens its gates to the world every April but otherwise is so secretive that it won’t confirm how many members it has, let alone name them.

From Los Angeles Times • Apr. 12, 2026

"We can confirm that the Department will host a meeting next week to discuss ongoing ceasefire negotiations with Israel and Lebanon," a US State Department official said.

From Barron's • Apr. 10, 2026

He said shortly afterwards they called again to confirm he was not on camp and they were contacting the police.

From BBC • Apr. 10, 2026

It didn’t confirm that the home belonged to Altman or that the business targeted was OpenAI.

From The Wall Street Journal • Apr. 10, 2026

“True,” said Kojo, nodding to confirm he understood what Jake was really saying.

From "The Smartest Kid in the Universe" by Chris Grabenstein

Related Words

• affirm
• approve
• back
• certify
• corroborate
• endorse
• establish
• explain
• sign
• substantiate
• support
• uphold
• verify