Vibrato (noun)

1. A slight, regular variation in the pitch of a sustained musical note, used to add expression and warmth to the sound.
2. A small, rapid variation of pitch in a person's voice when singing or speaking.

Origin:

From the italian word "vibrato" meaning "vibration".

Examples:

1. The singer used vibrato to add emotion to the song.
2. The violist used vibrato to add warmth to the sound.
3. The singer's vibrato was especially pronounced.
4. The vibrato in his voice added expression to his singing.
5. The vibrato in her voice gave the performance a sense of emotion.