Noun
a square-dance figure; two dancers approach each other and circle back to back before returning to their original places
Source: WordNetThrough it all, the quiet, deep-gray power of the river flows as steadily as time itself, a dance floor where ferries, barges, and sightseeing boats do their lumbering do-si-do past fabled and treacherous rocks. Source: Internet
These appear to do-si-do around the planet and change their positions from night to night — sometimes even from hour to hour! Source: Internet