A humming, buzzing, or droning sound; the action of making a sound of this kind. Later also: boasting, bragging. Cf. bum, v.2

A continuous steady deep humming or buzzing sound, esp. any continuous musical note of low pitch (also more fully drone note).

A single unvaried tone; a monotone. Obsolete. rare.

Continuous emission of a steady deep humming or buzzing sound; an instance of this.

Lack of variety or interest; tedious repetition or routine; the quality of being dull, unvarying, lifeless, etc.

A humming, buzzing, or droning sound. Cf. bum, v.2 1b, bumble, n.1 3.

In extended use: monotonous or mournful sound.

An imitation of the sound of a stringed instrument or instruments, esp. when monotonously played; strumming; a monotonous air. Also attributive.

An echoic word representing various sounds, esp. the tones produced by ‘thrumming’ a guitar or similar instrument; also dialect the purring of a cat.