Definitions
1.nounThe sound of one who warbles; singing with trills or modulations.
2.nounIn 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.
3.verbTo modulate a tone's frequency.
4.verbTo sing like a bird, especially with trills.
5.verbTo cause to quaver or vibrate.
6.verbTo be quavered or modulated; to be uttered melodiously.