from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A powerful adviser or decision-maker who operates secretly or unofficially. Also called gray eminence.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A secret or unofficial decision-maker; the power behind the throne.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. (French) a person who exercises power or influence in certain areas without holding an official position
French, the power behind the throne : éminence, power + grise, feminine of gris, gray, shadowy.(American Heritage® Dictionary of the English Language, Fourth Edition)
From French éminence ("power") + grise ("gray") (Wiktionary)