o·ver·drive / ˈōvərˌdrīv/ • n. a gear in a motor vehicle providing a gear ratio higher than that of the drive gear or top gear, so that engine speed and fuel consumption are reduced in highway travel. ∎ a state of high or excessive activity: the city's worried public relations arm went into overdrive. ∎ a mechanism that permits a higher than normal operating level in a piece of equipment, such as the amplifier of an electric guitar.• v. [tr.] [usu. as adj.] (overdriven) drive or work to exhaustion: the overdriven mothers of ten or eleven hungry children.