D is for Drone

A drone is a small aircraft that flies without a pilot inside it. It is controlled remotely by a person on the ground or programmed to fly automatically. The word drone began to be used for pilotless aircraft in the early 1900s. The name was inspired by male bees, also called drones, which do not gather food and were used as a metaphor for machines that operate without a human inside.

A drone is a low, steady, continuous sound that does not change much in pitch. It often describes background noises such as engines, insects, or machinery. The word comes from the sound made by male honeybees, called drones, whose deep buzzing noise inspired the use of the word for any similar humming sound.