dated A rounded knob mounted to the steering wheel of an automobile so that it may be steered with one hand. So called because the driver (typically male) is able to place his arm around his girlfriend or wife. My grandfather gave me his old Cadillac, which still had the necker's knob on the wheel from when he first started courting my grandmother.
See also: knob
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.