Definition
In radio communications, to confirm to the sender that their message has been received and understood. The acknowledgment is given by the receiving station, typically by reading back instructions or by stating their callsign followed by a brief confirmation.
Plain English
Let the other person on the radio know you got their message and understood it.
Context Anchor
You will see or hear this in radio communication with air traffic control, ground control, tower, or another pilot.
Derivation
From the older English 'acknow,' meaning to recognize or admit, combined with 'knowledge.' In radio use, it carries the same idea — you are letting the sender know that their message has reached you and been understood.
Why Pilots Care
Correct acknowledgment prevents miscommunication of clearances, instructions, and traffic information that could compromise flight safety.
Intuition Check
Acknowledge does not mean obey blindly or repeat every word automatically. In this context, it means confirm that you received and understood the message.
Example Sentence 1
The controller issued the descent clearance and waited for the pilot to acknowledge before turning to the next aircraft.
Example Sentence 2
After the controller issued a traffic advisory, the pilot acknowledged with 'traffic in sight.'