B1
to make an arrangement or meeting certain, often by telephone or in writing
Dictionary examples:
She confirmed her vacation plans, but forgot to confirm her boss's approval. (0.0)
I confirmed my alarm for 6 AM, but my brain hasn't confirmed it'll wake up. (0.0)
I confirmed my dentist appointment, but forgot to confirm my toothbrush's attendance. (0.0)
I've accepted the job over the phone, but I haven't confirmed in writing yet. (34.5)
Flights should be confirmed 48 hours before departure. (35.3)
Six people have confirmed that they will be attending and ten haven't replied yet. (39.7)