drone 1 
(drōn)
(drōn)n.
1. A male bee, especially a honeybee, that is characteristically stingless, performs no work, and produces no honey. Its only function is to mate with the queen bee.
2. An idle person who lives off others; a loafer.
3. A person who does tedious or menial work; a drudge: "undervalued drones who labored in obscurity" (Caroline Bates).
4. A remotely controlled or autonomous aircraft with no pilot on board. Also called unmanned aircraft system.
[Middle English, from Old English drān. Sense 4, originally 1930s US naval jargon introduced by Commander (later Rear Admiral) Delmer Fahrney (1898-1984), in reference to the fact that such pilotless aircraft, at first used for target practice, were controlled by an operator on the ground or in a mother ship or aircraft, likened to a queen bee.]