verb

make a low, steady continuous sound like that of a bee.

the computers hummed

purr,whir,throb,vibrate,murmur,buzz,thrum,drone,susurrate,bombinate

noun

a low, steady continuous sound.

the hum of insects

murmur,murmuring,drone,droning,vibration,purr,purring,buzz,buzzing,whir,whirring,throb,throbbing,thrum,thrumming,susurration,susurrus,bombination