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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.


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

"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

Other Word Forms

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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Vocabulary lists containing confirm

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.

But he appeared to confirm reports that the deal under discussion could push the issue of Iran's enriched uranium stocks until later, while opening the Strait of Hormuz, which is crucial for oil traffic.

From Barron's • May 27, 2026

People can check something called an IRS tax transcript to confirm whether they were charged a penalty and when.

From MarketWatch • May 27, 2026

After a turbulent season that saw Liverpool confirm Champions League qualification only on the last day, BBC Sport grades each of last summer's signings.

From BBC • May 26, 2026

Among them was the original type specimen of the Himalayan pit viper, which helped researchers confirm the snake's true scientific identity.

From Science Daily • May 26, 2026

He glanced around to confirm we were alone.

From "The Bletchley Riddle" by Ruta Sepetys and Steve Sheinkin

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