- (literally) back to back
- a move in square dancing in which two dancers face each other, then step forward and left until they have right shoulders adjacent, then move to a position where they are back to back, then move to have left shoulders adjacent, then return to facing each other
Square dancing is called in English everywhere except in parts of French Canada. The term used when calling in English is spelled several ways, including Dos a Dos, Dosado, Do-Sa-Do, Dosido, Do-Si-Do. Note that none of these is quite the same as the original French phrase.