"warble" definition, meaning, and origin

Noun

The sound of one who warbles; singing with trills or modulations.
- The blackbirds and robins and and^([sic]) tits and finches shout at each other, chups and warbles and chirrups that, loosely translated, mean “Fancy a shag?”, “Get OFF my land” or “I’ve got a great big tonker.” - 2015...
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.

Perhaps onomatopoeic.

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.

From Middle English werble (at least for the noun), from Frankish *werbel (mole cricket), cognate to Walloon waerbea.

To modulate a tone's frequency.
To sing like a bird, especially with trills.
- Her voice more sweet than warbling sound, Tho’ sung by nightingale or lark, Her eyes such lustre dart around, Compar’d to them the sun is dark. - a. 1722, Matthew Prior, “Non Pareil”, in H. Bunker Wright, Monroe K....
- In the swamp in secluded recesses, / A shy and hidden bird is warbling a song. - 1865, Walt Whitman, “When Lilacs Last in the Dooryard Bloom’d”, in Sequel to Drum-Taps: When Lilacs Last in the Dooryard Bloom’d and other...
To cause to quaver or vibrate.
- touch the warbled string - 1634, John Milton, “Arcades”, in Poems of Mr. John Milton, […], London: […] Ruth Raworth for Humphrey Mosely, […], published 1646, →OCLC:
To be quavered or modulated; to be uttered melodiously.
- The wailings of a maiden I recite, / A maiden fair, that Sparabella hight. / Such ſtrains ne'er warble in the linnet's throat, / Nor the gay goldfinch chaunts ſo ſweet a note, [...] - 1714, J[ohn] Gay, “Wednesday; or,...