The act of admitting the existence or truth of something: acknowledgment that the service was poor.
Recognition or notice: peace based on acknowledgment of a nation's sovereignty. An expression of thanks or appreciation: included acknowledgments of people who helped in making the book.
An answer or response in return for something: sent an acknowledgment of receipt of the letter.
Law The formal avowal of an act before a legally empowered officer, such as a judge or notary public, to ensure that the act will be legally recognized.