eminence grise

Even before his long career in government ended, he was an éminence grise in American public life.

Bill Clinton could have a relationship with an intern and still be greeted as an éminence grise years later.

Indeed, no one embodies knowing youthfulness more than Oscar de la Renta, the éminence grise of American fashion.

Take as an illustration of the contrary practice such a masterpiece in its way as Gérôme's "Éminence Grise."