acknowledgement

noun9

1. •
   The act of acknowledging
2. •
   The act of recognizing in a particular character or relationship; recognition of existence, authority, truth, or genuineness.

   • He just grunted in acknowledgment of my greeting.
3. •
   A recognition as genuine or valid; an avowing or admission in legal form.
4. •
   The act of a person admitting a child as their own.
5. •
   A reward or other expression or token of gratitude.
6. •
   An expression of gratitude for a benefit or an obligation.
7. •
   A message from the addressee informing the originator that the originator's communication has been received and understood.
8. •
   A response (ACK) sent by a receiver to indicate successful receipt of a transmission (See Wikipedia article on transmission).
9. •
   A formal statement or document recognizing the fulfillment or execution of a legal requirement or procedure.