confirm
Americanverb (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.
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
Other Word Forms
Derived Forms
-
unconfirmverb (used with object)
-
confirmatoryadjective
-
reconfirmverb (used with object)
-
confirmableadjective
-
confirmernoun
-
nonconfirmingadjective
-
confirmabilitynoun
-
confirminglyadverb
-
preconfirmverb (used with object)
-
unconfirmabilitynoun
Conjugated Forms
Present
-
has confirmedperfect 3rd person singular
-
have confirmedperfect
-
have been confirmingperfect progressive
-
has been confirmingperfect progressive 3rd person singular
-
are confirmingprogressive
-
confirmingparticiple
-
confirmssingular 3rd person
-
is confirmingprogressive 3rd person singular
-
am confirmingprogressive 1st person singular
Past
-
had confirmedperfect
-
was confirmingprogressive singular
-
were confirmingprogressive plural
-
confirmedparticiple
-
confirmedsimple
-
had been confirmingperfect progressive
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."
Vocabulary lists containing confirm
Jim Burke's Academic Vocabulary List
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The SAT: Language of the Test, List 3
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The Language of Standardized Tests, List 2
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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.
Confirm this by checking the browser’s address bar, which typically displays a lock icon indicating that you’re accessing the website securely.
From Salon • Jun. 2, 2026
They will then need to confirm their identity through a TSA system known as TSA Confirm ID, which can check a person’s identity against passport data and other personally identifying information.
From The Wall Street Journal • Dec. 1, 2025
The C.I.A. mission recalled in “Neither Confirm Nor Deny,” Philip Carter’s neat and steadily paced documentary, sounds like the stuff of a Tom Clancy Cold War thriller.
From New York Times • Sep. 21, 2023
Confirm that you’re running the latest version of Windows.
From Seattle Times • Mar. 25, 2023
"O bid our vain endeavors cease, Revive the just designs of Greece; Return in all thy simple state, Confirm the tale her sons relate."
From The Chainbearer Or, The Littlepage Manuscripts by Cooper, James Fenimore
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
