To vary irregularly; to swing.
To cause to vary irregularly.
To undulate.
To be irresolute; to waver.
To brandish; to swing to and fro.
To use vibrato.
To affect with vibratory motion; to set in vibration.
To resonate.
To shake with small, rapid movements to and fro.
To mark or measure by moving to and fro.
The setting, on a portable electronic device, that causes it to vibrate rather than sound any (or most) needed alarms.