verb. ['ˈhʌm'] sing with closed lips.
adjective. so lacking in interest as to cause mental weariness.
noun. ['ˈhʌm'] the state of being or appearing to be actively engaged in an activity.
verb. ['ˈhʌm'] make a low continuous sound.
noun. ['ˈhʌm'] a humming noise.
verb. ['ˈhʌm'] sound with a monotonous hum.
verb. ['ˈhʌm'] be noisy with activity.