Definition of: hum

(hum) v. hummed, hum·ming v.i.
1. To make a low, continuous, buzzing sound, as a bee.
2. To sing with the lips closed, not articulating the words.
3. To give forth a confused, indistinct sound, as of mingled voices.
4. To pause in speaking, as from confusion; hem.
5. Colloq. To be busily active: The office hummed.
—v.t.
6. To sing, as a tune, with the lips closed.
7. To put into a specified state or condition by humming: to hum someone to sleep. See synonyms under SING.
—noun A low, monotonous, or inarticulate sound (as of h’m).
—interj. A sound as of h’m or hem. [Imit.]
—hum′mer noun