Noun

(en noun)

(historical) A member of a Muslim militant group responsible for murdering Christian leaders during the Crusades.

*, II.29:

The Assassines , a nation depending of Phœnicia, are esteemed among the Mahometists of a soveraigne devotion and puritie of maners; they hold, that the readiest and shortest way to gaine Paradise, is to kill some one of a contrary religion.

Someone who intentionally kills a person, especially a professional who kills a public or political figure.

* {{quote-magazine, date=2013-06-29, volume=407, issue=8842, page=55, magazine=(The Economist)

, title= Travels and travails , passage=Even without hovering drones, a lurking assassin , a thumping score and a denouement, the real-life story of Edward Snowden, a rogue spy on the run, could be straight out of the cinema. But, as with Hollywood, the subplots and exotic locations may distract from the real message: America’s discomfort and its foes’ glee.}}

Any ruthless killer.

Noun

(en noun)

The male monarch or ruler of an empire.

(medieval political theory ) Specifically, the ruler of the Holy Roman Empire; the world-monarch.

The Investiture Controversy was a conflict between the Emperor and the Pope.

A large, relatively valuable marble in children's games.

* 2001 , Paul Webley, The economic psychology of everyday life (page 39)

But marbles are not only used to play games: they are also traded. In this market, the value of the different kinds of marbles (oilies, emperors , etc.) is determined by local supply and demand and not by the price of the marbles