Real Dictionary

drone
verb: If something drones, it makes a low, continuous, dull noise.

drone in American English 1
a continuous and monotonous humming or buzzing sound
to make a continuous and monotonous humming or buzzing sound
to utter in a dull, monotonous tone
noun: the male of the honeybee and other bees, stingless and making no honey

drone in American English 2
a male bee or ant which serves only in a reproductive capacity and does no work
to live in idleness; loaf
intransitive verb: to make a dull, continued, low, monotonous sound; hum; buzz
noun: a continuous low tone produced by the bass pipes or bass strings of musical instruments
transitive verb: to say in a dull, monotonous tone

drone in British English 1
noun: a male bee in a colony of social bees, whose sole function is to mate with the queen

drone in British English 2
noun: a monotonous low dull sound
verb: to make a monotonous low dull sound; buzz or hum