The sound of one who warbles; singing with trills or modulations.

(military) In naval mine warfare, the process of varying the frequency of sound produced by a narrowband noisemaker to ensure that the frequency to which the mine will respond is covered.

A lesion under the skin of cattle, caused by the larva of a bot fly of genus Hypoderma.

A small hard swelling on a horse's back, caused by the galling of the saddle.

(transitive) To modulate a tone's frequency.

(transitive) To sing like a bird, especially with trills.

(transitive) To cause to quaver or vibrate.

(intransitive) To be quavered or modulated; to be uttered melodiously.