Etymology
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coup de grace (n.)

"a single blow or stroke, dispatching one condemned or mortally wounded to put an end to misery," 1690s, from French coup de grce, literally "stroke of grace;" the merciful death-blow that ends another's suffering (see coup + grace (n.)).

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coup de foudre (n.)

"sudden, unforeseen occurrence," 1779, from French coup de foudre, literally "stroke of lightning," also "love at first sight" (see coup).

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coup d'etat (n.)

1640s, from French coup d'étate, literally "stroke of the state" (see coup). Technically any sudden, decisive political act, especially an important and unexpected change in the form and methods of a government, but in 20c. popularly restricted to the overthrow of a government.

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