Former students of Le Rosey, at Rolle, Vaud, Switzerland, are called in French anciens Roséens (f. anciennes Roséennes), or more simply anciens (f. anciennes) or Roséens (Roséennes). When referring to both genders together, the masculine form is used.
In English, the French terms are used as well as the alternatives Rosean, Roseyan, Old Rosean, former Rosean, etc.