betray (v.)youdaoicibaDictYouDict
late 13c., bitrayen "mislead, deceive, betray," from be- + obsolete Middle English tray, from Old French traine "betrayal, deception, deceit," from trair (Modern French trahir) "betray, deceive," from Latin tradere "hand over," from trans- "across" (see trans-) + dare "to give" (see date (n.1)). Related: Betrayed; betraying.
CassandrayoudaoicibaDictYouDict
fem. proper name, from Greek Kasandra, Kassandra, daughter of Priam of Troy, seduced by Apollo who gave her the gift of prophecy, but when she betrayed him he amended it so that, though she spoke truth, none would believe her. Used figuratively since 1660s.

The name is of uncertain origin, though the second element looks like a fem. form of Greek andros "of man, male human being." Watkins suggests PIE *(s)kand- "to shine" as source of second element, hence possibly "praise of men."
cuckold (n.)youdaoicibaDictYouDict
mid-13c., kukewald, from Old French cucuault, from cocu (see cuckoo) + pejorative suffix -ault, of Germanic origin. So called from the female bird's alleged habit of changing mates, or her authentic habit of leaving eggs in another bird's nest.

In Modern French the identity is more obvious: Coucou for the bird and cocu for the betrayed husband. German Hahnrei (13c.), from Low German, is of obscure origin. The second element seems to be connected to words for "ardent," and suggests perhaps "sexually aggressive hen," with transferal to humans, but Kluge suggests rather a connection to words for "capon" and "castrated." Related: Cuckoldry.
DelilahyoudaoicibaDictYouDict
"temptress, treacherous lover," 1590s, from the name of the woman who seduced and betrayed Samson in Judges, from Hebrew Delilah, literally "delicate, languishing, amorous," from Semitic root d-l-l "to hang down, to languish."
MunichyoudaoicibaDictYouDict
Bavarian capital, German München, from root of Mönch "monk" (see monk); founded 1158 as a market town by Benedictine monks. In allusions to "appeasement" it is from the meeting of German, British, French and Italian representatives there in Sept. 29, 1938, which resulted in the cession of Sudetenland to Germany in exchange for Hitler's pledges.
During the flight Daladier sat silent and morose, worried about the reception he would receive at Le Bourget, about how the French would react to his having betrayed Czechoslovakia and France's promises. As the plane circled for landing, he and others saw a massive crowd awaiting them. Expecting jeers, hisses, rotten fruit, and maybe worse, Daladier declared stolidly: 'They are going to mob me, I suppose. ... I appreciate their feelings,' and insisted on absorbing their wrath by being the first off the plane. But as he stood dumbfounded on the gangplank, thousands surged forward carrying flags and flowers, shouting 'Hurrah for France! Hurrah for England! Hurrah for peace!' Daladier turned back to Léger and cursed, 'The God-damned fools!' [Benjamin F. Martin, "France in 1938"]
Tarpeian rock (n.)youdaoicibaDictYouDict
rock face on the Capitoline Hill in Rome, from which persons convicted of treason were thrown headlong, from Latin (mons) Tarpeius "(rock) of Tarpeia," said to have been a Vestal virgin who betrayed the capitol to the Sabines and was buried at the foot of the rock. Her name probably is of Etruscan-Tyrrhenian origin.