From lines, waves, two-faced lines, couples, box formation, columns, etc.: Those designated will exchange places with each other by walking forward in a larger or smaller arc. Both traders will reverse facing directions. When dancers or couples must pass each other in the process of trading, they pass right shoulders. (Wheel Across can also be termed "Couples Trade".) BACKGROUND NOTE: The term "Trade" was suggested by Lloyd Litman. The idea of Trade had been in use for some years before that under a variety of names, some directional, some not so directional.
Lloyd Litman 1965
This definition is from The Handbook of Modern Square Dancing by Jay King.
It is provided here for informational and educational purposes only.