n. 鸟啭鸣；颤声
v. 鸟鸣；用柔和的颤声唱（warble 的现在分词）

Warble \War"ble\, v. t. [imp. & p. p. {Warbled}; p. pr. & vb. n.
{Warbling}.] [OE. werbelen, OF. werbler; of Teutonic origin;
cf. G. wirbeln to turn, to warble, D. wervelen, akin to E.
whirl. See {Whirl}.]
1. To sing in a trilling, quavering, or vibratory manner; to
modulate with turns or variations; to trill; as, certain
birds are remarkable for warbling their songs.

2. To utter musically; to modulate; to carol.

If she be right invoked in warbled song. --Milton.

Warbling sweet the nuptial lay. --Trumbull.

3. To cause to quaver or vibrate. ``And touch the warbled
string.'' --Milton.