transitive. To utter with humming; to sing with closed lips and without articulation.

transitive. To hum (a tune). Also figurative.

transitive. To sing, hum, or whistle (a tune) softly.

transitive. = sowff, v.

transitive. To sing (a tune) without words; to hum.

transitive. To recite or tell in a ‘sing-song’ or monotonous way; also, to hum over (a melody).

transitive and intransitive. To sing (a tune) in a low undertone; to hum.