vi·bra·to 
(və-brätō, vī-)
(və-brätō, vī-)n. pl. vi·bra·tos
A tremulous or pulsating effect produced in an instrumental or vocal tone by minute and rapid variations in pitch.
[Italian, from Late Latin vibrātus, a quivering, from Latin, past participle of vibrāre, to vibrate; see VIBRATE.]