acknowledgeacknowledgeacknowledgesacknowledgedacknowledgingverb (acknowledges, acknowledging, acknowledged)1to agree or accept that something is true: He acknowledged that he had made a mistake.2to write to somebody who has sent you a letter, etc. to say that you have received it: She never acknowledged my letter.▶ acknowledgementacknowledgementacknowledgementsnoun: I didn't receive an acknowledgement of my application.