From parallel waves: Ends Trade and Roll one half (i.e., U-turn back by turning inward) as the centers quickly Run into the temporarily vacant end spots and Roll to arm turn the one across 3/4 around. Finishes in parallel waves (right hand waves become left hand and vice versa).
"Foggy" Thompson 1973
This definition is from The Handbook of Modern Square Dancing by Jay King.
It is provided here for informational and educational purposes only.