two-step

two-step, ballroom dance appearing in about 1890 in the United States. Its origins are unclear but may include the polka, galop, or waltz. The dance consists of sliding steps to the side in 2/4 time. It was one source of the fox-trot, which in about 1920 overtook it in popularity, and the term two-step often refers to the fox-trot (q.v.).