Definition of "assassin"

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 […].

1603, Michel de Montaigne, chapter 29, in John Florio, transl., The Essayes […], book II, London: […] Val[entine] Simmes for Edward Blount […]

The hand that held the bond of so many jarring interests lay powerless beneath the pall. The perils of war had been about him, and the midnight assassin had watched his path; yet he died quietly in his bed.

1834, L[etitia] E[lizabeth] L[andon], chapter XXII, in Francesca Carrara. […], volume II, London: Richard Bentley, […], (successor to Henry Colburn), page 233

What has violence ever accomplished? What has it ever created? No martyr's cause can ever be stilled by an assassin’s bullet.

1968, Robert F. Kennedy, On the Mindless Menace of Violence

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.

2013 June 29, “Travels and travails”, in The Economist‎, volume 407, number 8842, page 55