do-si-do 
(dōsē-dō)
(dōsē-dō)n. pl. do-si-dos
1. A movement in square dancing in which two dancers approach each other and circle back to back, then return to their original positions.
2. The call given to signal such a movement.
[Alteration of French dos à dos, back to back : dos, back (from Old French; see DOSSIER) + à, to; see BLACK-A-VISED.]