HUMS

noun

1. A hummed tune, i.e. created orally with lips closed.
2. An often indistinct sound resembling human humming.
3. Busy activity, like the buzz of a beehive.

verb

1. To make a sound from the vocal chords without pronouncing any real words, with one's lips closed.
2. To express by humming.
3. To drone like certain insects naturally do in motion, or sounding similarly