rotating

/ˈrō-ˌtāt/

Latin rotatus, past participle of rotare, from rota wheel

verb

  1. to perform an act, function, or operation in turn

  2. to pass or alternate in a series

  3. to turn about an axis or a center : revolve; especially : to move in such a way that all particles follow circles with a common angular velocity about a common axis

idiom

  1. by taking turns

The doctors take weekend call on a rotating basis.