From parallel two-faced lines: Ends Circulate once and a half while the centers arm turn 3/4. New centers Trade. The two end couples promenade one quarter and wheel to face the center. Lonesome dancers turn to face in and step forward as ends of a wave with the center. If starting two faced lines faced clockwise, the wave in the center will be right handed. If starting two faced lines faced counterclockwise, the wave in the center will be left handed.
Curt Bauter 1975
This definition is from The Handbook of Modern Square Dancing by Jay King.
It is provided here for informational and educational purposes only.