Definitions

1. noun

a low, continuous sound, especially one made by an insect or a machine.

“The hum of the refrigerator filled the quiet room.”

2. verb

to make a low, continuous sound.

“The generator was humming loudly outside.”

3. verb

to be filled with a low, continuous sound.

“The city hums with activity during rush hour.”

4. interjection

an expression of satisfaction or pleasure.

“Hum, this cake is delicious!”