Drone
Part of speech: noun
Definition: A male bee or wasp, which does not work but can fertilise the queen. A remotely controlled aircraft. A low-pitched hum or buzz. One who performs menial or tedious work; a drudge. One of the fixed-pitch pipes on a bagpipe. A genre of music similar to that of noise.
Part of speech: verb
Definition: To produce a low-pitched hum or buzz. To speak in a monotone way.
Monotone
Part of speech: verb
Definition: To speak in a monotone.
Part of speech: adjective
Definition: having a single unvaried pitchproperty of a function to be either decreasing or increasing
Part of speech: noun
Definition: A single unvaried tone of speech or a sound