Plain English Meaning
The U.S. government department in charge of the military. In aviation, it is important because it owns and runs systems like GPS that civilian pilots also rely on.
Full Definition
The U.S. federal executive department responsible for the armed forces. In aviation contexts, the DOD develops, certifies, and operates many navigation and surveillance systems (such as GPS) that are also used by civil aviation, and it publishes flight information products jointly with or alongside the FAA.
Context Anchor
Seen in FAA training material when a system, standard, or example has a military connection or came from military aviation use.
Why Pilots Care
Pilots may see DOD references when checking military , joint-use airports, or equipment specifications that meet defense .