What exactly is a "drone"?
General usage
According to Etymology Online The term drone, meaning &quot;pilotless aircraft&quot; dates from 1946.
It evidently encompasses all types of aircraft where no onboard human pilot is needed, either because the human pilot operates the aircraft remotely (still true for most types of military &quot;drone&quot; aircraft I believe) or because the aircraft systems are capable of full autonomy during some of all of a flight.
The earliest uses were probably &quot;target drones&quot;. Which is what Wikipedia suggests.
The term does seem to have supplanted &quot;RC aircraft&quot; for modern small RC aircraft, especially those which carry a camera and/or from which their operators derive some value other than simply from mastering the skill of flying the vehicle.
English language is defined by usage, not by edict. So this isn't subject to rulings or appeal.
Lawmakers or other bodies might define the term more narrowly but this doesn't affect other uses of the same word.
FAA definition
The FAA talks mainly about &quot;model aircraft&quot; and &quot;unmanned model aircraft&quot; (ref.) and about Unmanned Aircraft(UA)  or Unmanned Aerial Systems (UAS). (ref.)
They usually don't use the term drone or define it, but from their FAQ it seems they consider the terms drone and UAS to be equivalent

Myth #7:The FAA is lagging behind other countries in approving commercial drones.
Fact– This comparison is flawed.  The United States has the busiest, most complex airspace in the world, including many general aviation aircraft that we must consider when planning UAS integration, because those same airplanes and small UAS may occupy the same airspace.