Noun

(en noun)

The act, manner or style of executing (actions, maneuvers, performances).

*

The state of being executed (accomplished).

The battle plan was successfully executed .

The act of putting to death or being put to death as a penalty, or actions so associated.

(legal) The carrying into effect of a court judgment, or of a will.

(legal) The formal process by which a contract is made valid and put into binding effect.

(computing) The carrying out of an instruction, program or program segment by a computer.

The entire machine slowed down during the execution of the virus checker .

Whenever the matrix inversion function executed the program crashed.

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.