Available Definitions:
1) v. i. - To tremble; to vibrate; to shake.
2) v. i. - 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
3) v. t. - To utter with quavers.
4) n. - A shake, or rapid and tremulous vibration, of the voice, or of an instrument of music.
5) n. - An eighth note. See Eighth .