Noun

• S: (n) drone (stingless male bee in a colony of social bees (especially honeybees) whose sole function is to mate with the queen)
• S: (n) monotone, drone, droning (an unchanging intonation)
• direct hypernym / inherited hypernym / sister term
• S: (n) intonation, modulation, pitch contour (rise and fall of the voice pitch)
• derivationally related form
• S: (n) dawdler, drone, laggard, lagger, trailer, poke (someone who takes more time than necessary; someone who lags behind)
• S: (n) drone, pilotless aircraft, radio-controlled aircraft (an aircraft without a pilot that is operated by remote control)
• S: (n) drone, drone pipe, bourdon (a pipe of the bagpipe that is tuned to produce a single continuous tone)

Verb

• S: (v) drone (make a monotonous low dull sound) "The harmonium was droning on"
• S: (v) drone, drone on (talk in a monotonous voice)