Etymology From Middle English traitor, traitour, traytour, from Old French traïtor (French traître), from Latin trāditor. Displaced native Middle English swike from Old English swica (“traitor”), and Middle English proditour and traditour borrowed directly from Latin. The general Old English word denoting "traitor" was lǣwa or lǣwend. Doublet of traditor and treason.
1
Someone who violates an allegiance and betrays their country; someone guilty of treason; one who, in breach of trust, delivers their country to an enemy, or yields up any fort or place entrusted to their defense, or surrenders an army or body of troops to the enemy, unless when vanquished.
After World War I, the communists and Jews were accused to be traitors by the German right wing (the "stab-in-the-back myth"), ultimately culminating in their persecution and massacre.
My Lord of Hereford here whom you call King, / Is a foule traitour to proud Herefords King, / And if you crowne him let me propheſie, / The bloud of Engliſh ſhall manure the ground, / And future ages groane for this foule act, [...]1595 December 9 (first known performance), [William Shakespeare], The Tragedie of King Richard the Second. […] (First Quarto), London: […] Valentine Simmes for Androw Wise, […], published 1597, →OCLC, [Act IV, scene i]:
1 more example
Yes, that was Vice President Spiro Agnew commemorating the "loyalty" of literal traitors. But what can you really expect from a man whose name rearranged spells "grow a penis."2017 October 8, “Confederacy” (14:45 from the start), in Last Week Tonight with John Oliver, season 4, episode 26, John Oliver (actor), via HBO:
2
Someone who takes arms and levies war against their country; or one who aids an enemy in conquering their country.
3
Broadly One who betrays any confidence or trust.
It's second nature now to think myself a traitor To myself, to all I've ever burdened with my rotting visage I can't breathe, the weight of all I've disappointed crushes me If I were happy, it would feel as if I couldn't trust me2019, Patricia Taxxon, “Cold Water”, in Doraemon:
It took you two weeks To go off and date her Guess you didn't cheat But you're still, you're still a traitor Yeah, you're still a traitor2021, Olivia Rodrigo, Dan Nigro, “Traitor”, in Sour, performed by Olivia Rodrigo:
Etymology From Middle English traitor, traitour, traytour, from Old French traïtor (French traître), from Latin trāditor. Displaced native Middle English swike from Old English swica (“traitor”), and Middle English proditour and traditour borrowed directly from Latin. The general Old English word denoting "traitor" was lǣwa or lǣwend. Doublet of traditor and treason.
1
To act the traitor toward; to betray; to deceive.
traitor
adj
Etymology From Middle English traitor, traitour, traytour, from Old French traïtor (French traître), from Latin trāditor. Displaced native Middle English swike from Old English swica (“traitor”), and Middle English proditour and traditour borrowed directly from Latin. The general Old English word denoting "traitor" was lǣwa or lǣwend. Doublet of traditor and treason.
1
Traitorous.
to find a subject staid and wise Already half turn'd traitor by surprise1735, Alexander Pope, “The Second Satire of Dr. John Donne”, in The Works of Mr. Alexander Pope, volume II, London: […] J. Wright, for Lawton Gilliver […], →OCLC: