quaver
Webster 1828
QUA'VER, verb intransitive 1. To shake the voice; to utter or form sound with rapid vibrations, as in singing; to sing with tremulous modulations of voice.2. To tremble; to vibrate.The finger - moved with a quavering motion.QUA'VER, noun 1. A shake or rapid vibration of the voice, or a shake on an instrument of music.2. A note and measure of time in music, equal to half a crotchet or the eighth of a semibreve