hum

中文： 嗡嗡声、哼唱、忙碌声

1. A hummed tune, i.e. created orally with lips closed.
2. An often indistinct sound resembling human humming. · They could hear a hum coming from the kitchen and found the dishwasher on.
3. Busy activity, like the buzz of a beehive.
4. An imposition or hoax; humbug. (dated)
5. A phenomenon, or collection of phenomena, involving widespread reports of a persistent and invasive low-frequency humming, rumbling, or droning noise not audible to all people.

复数 hums