Pronunciation: (kun-fûrm'),[key] —v.t. 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.