—v.i. 1. to make a low, continuous, droning sound.
2. to give forth an indistinct sound of mingled voices or noises.
3. to utter an indistinct sound in hesitation, embarrassment, dissatisfaction, etc.; hem.
4. to sing with closed lips, without articulating words.
5. to be in a state of busy activity: The household hummed in preparation for the wedding. 6. Brit. Slang.to have a bad odor, as of stale perspiration.
—v.t. 1. to sound, sing, or utter by humming: to hum a tune. 2. to bring, put, etc., by humming: to hum a child to sleep.
—n. 1. the act or sound of humming; an inarticulate or indistinct murmur; hem.
2. Audio.an unwanted low-frequency sound caused by power-line frequencies in any audio component.