Military slang meaning: "I've received and understood your message in it's entirely".

Contrasts with "No Copy", a phrase used when a message was partially or fully lost. Originally came as a response to the phrase "How Copy?", a term a transmitter asks a recipient to find out if their message has been properly relayed. It has since slipped into the military colloquial.
1Lt Martin: "I need you present at 1615 tomorrow to discuss our new operations orders."

1Lt Daniels: "Good copy."
by crymsonwynters September 12, 2020
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