Drone

someone who takes more time than necessary; someone who lags behind

a pipe of the bagpipe that is tuned to produce a single continuous tone

an aircraft without a pilot that is operated by remote control

an unchanging intonation

stingless male bee in a colony of social bees (especially honeybees) whose sole function is to mate with the queen

talk in a monotonous voice

make a monotonous low dull sound