verb (used with object)
  1. to establish the truth, accuracy, validity, or genuineness of; corroborate; verify: This report confirms my suspicions.
  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.
  4. to make firm or more firm; add strength to; settle or establish firmly: Their support confirmed my determination to run for mayor.
  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.

Origin of confirm

1250–1300; < Latin confirmāre to strengthen, confirm (see con-, firm1); replacing Middle English confermen < Old French < Latin, as above
Related formscon·firm·a·ble, adjectivecon·firm·a·bil·i·ty, nouncon·firm·er; Law. con·fir·mor [kon-fer-mawr, kuhn-fur-mer] /ˌkɒn fərˈmɔr, kənˈfɜr mər/, nouncon·firm·ing·ly, adverbnon·con·firm·ing, adjectivepre·con·firm, verb (used with object)re·con·firm, verb (used with object)un·con·firm, verb (used with object)un·con·firm·a·bil·i·ty, noun

Synonyms for confirm

Antonyms for confirm Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for reconfirm


verb (tr)
  1. to confirm (an arrangement, agreement, etc) againreconfirm your return flight on arrival


verb (tr)
  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 definitehe confirmed that he would appear in court
  3. to strengthen or make more firmhis story confirmed my doubts
  4. to make valid by a formal act or agreement; ratify
  5. to administer the rite of confirmation to
Derived Formsconfirmable, adjectiveconfirmatory or confirmative, adjectiveconfirmer, noun

Word Origin for confirm

C13: from Old French confermer, from Latin confirmāre, from firmus firm 1
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

Word Origin and History for reconfirm



mid-13c., confirmyn "to ratify," from Old French confermer (13c., Modern French confirmer) "strengthen, establish, consolidate; affirm by proof or evidence; anoint (a king)," from Latin confirmare "make firm, strengthen, establish," from com-, intensive prefix (see com-), + firmare "to strengthen," from firmus (see firm (adj.)). Related: Confirmative; confirmatory.

Online Etymology Dictionary, © 2010 Douglas Harper