1. A male bee, especially a honeybee, that is characteristically stingless, performs no work, and produces no honey: The only function of the drones is to mate with the queen bee.
2. Someone who does tedious or menial work; a drudge: Because shoveling out the cow barn is an endless task, one of the workers at the farm felt as if he were just a drone who was caught up by the repetitious tasks of the farm.
3. A pilotless air vehicle which is pre-programmed prior to launch to accomplish a set of functions with no further human intervention or it is operated by remote control from the ground: The military operated a drone as an air vehicle having no on-board pilot that is capable of receiving continuous or intermittent commands from far away.

Drones may also be controlled by on-board sensors to autonomously make mission adjustments.

4. A low continuous noise that goes on and on: Christa could hear the drones of the bees near her window screen.
5. Etymology: from Middle English which came from Old English dran, "a drone, a male bee"; given a figurative sense of "idler, lazy worker" because male bees make no honey. The meaning of "pilotless aircraft" is from 1946; apparently meaning, "a deep, continuous humming sound".

To speak in a monotonous tone; to make a dull, humming sound: Some people were falling asleep as the speaker droned on and on.

The politician was droning continuously about the shortcomings of his opponent.