noun
vibrato
vih-BRAH-toh/vɪˈbrɑːtəʊ/
A slight, regular variation in the pitch of a musical tone.
The violinist rocks a fingertip to create vibrato.

Etymology
Italian vibrato names a trembling musical effect, as if the sound were affected by strong emotion. Here that trembling takes the form of a slight wavering in pitch.
In context
My teacher used to get me to practice vibrato by going up and down the string and then gradually getting smaller and smaller and smaller until you get the rotations, the feeling in the arm, correct.
More examples
- Her voice had a warm, controlled vibrato.
- He practiced producing an even vibrato on the cello.
- Too much vibrato blurred the sustained note.
Forms
vibrato
vibrate verb — move rapidly back and forth