Definition of éminence grise in English:

éminence grise

noun

  • A person who exercises power or influence in a certain sphere without holding an official position.

    • ‘But the Hutton inquiry isn't the kind of thing that éminences grises and powers behind thrones are used to.’

Origin

1930s: French, literally ‘gray eminence’. The term was originally applied to Cardinal Richelieu's gray-cloaked private secretary, Père Joseph (1577–1638).

Pronunciation

éminence grise

/ˌɛmənəns ˈɡriz//ˌemənəns ˈɡrēz/