The Word 'HUM'

Hum (noun)

definition:
a humming noise

example:
"the hum of distant traffic"

Hum (noun)

definition:
the state of being or appearing to be actively engaged in an activity

Hum (verb)

definition:
sing with closed lips

example:
"The chorus hummed a melody."

Hum (verb)

definition:
make a low continuous sound

example:
"The refrigerator is humming"

Hum (verb)

definition:
sound with a monotonous hum

Hum (verb)

definition:
be noisy with activity