From The Collaborative International Dictionary of English v.0.48:
Quaver \Qua"ver\, v. t. To utter with quavers. [1913 Webster]
We shall hear her quavering them . . . to some sprightly airs of the opera. --Addison. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Quaver \Qua"ver\, n. 1. A shake, or rapid and tremulous vibration, of the voice, or of an instrument of music. [1913 Webster]
2. (Mus.) An eighth note. See Eighth. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Quaver \Qua"ver\, v. i. [imp. & p. p. Quavered; p. pr. & vb. n. Quavering.] [OE. quaven to shake, to tremble; cf. LG. quabbeln to shake, to be soft, of fat substances, quabbe a fat lump of flesh, a dewlap, D. kwabbe, and E. quiver, v.] 1. To tremble; to vibrate; to shake. --Sir I. Newton. [1913 Webster]
2. Especially, to shake the voice; to utter or form sound with rapid or tremulous vibrations, as in singing; also, to trill on a musical instrument [1913 Webster]