The practice (especially prevalent in midwestern states where cows are king) of waving at oncoming traffic by slightly raising the index finger of the right hand which is permanently positioned at the twelve o'clock position of the steering wheel. The wave is executed every time another vehicle is met on the road. It may or may not be accompanied by a nod of the head.
Dude, stop waving with your whole hand like a beauty queen when we meet someone on the road!!! You're in Nebraska now...gotta use the Beef Raiser Wave.