means A large, dense, moving mass of insects or other creatures (or, by extension, people or drones) that travels and acts together as one teeming group.

from From Old English 'swearm,' a word shared across the Germanic family — German 'Schwarm,' Old Norse 'svarmr.' Its deeper root may be tied to a sense of 'humming' or 'buzzing,' which would make the word itself a small echo of the sound a thousand wings make — the noise naming the thing that makes it.