■ noun
1》 a gear in a motor vehicle providing a gear ratio higher than that of the usual top gear.
2》 a state of high or excessive activity.
3》 a mechanism allowing the exceeding of a normal operating level in equipment, especially the amplifier of an electric guitar.
■ verb [usu. as adjective ~n ]
1》 drive or work to exhaustion.
2》 give (an electric guitar) a distorted sound.