Military coup d'état

A coup d'état (/ˌkuː deɪˈtɑː/  listen ; French: [ku deta]), also known simply as a coup (/kuː/), a putsch (/pʊtʃ/), or an overthrow, is the illegal and overt seizure of a state by the military or other elites within the state apparatus.

The phrase coup d'état (French pronunciation: ​[ku deta]) is French, literally meaning a "stroke of state" or "blow against the state." In French the word "État," denoting a sovereign political entity, is capitalized.

Although the concept of a coup d'état has been featured in politics since antiquity, the phrase is of relatively recent coinage; the Oxford English Dictionary identifies it as a French expression meaning a "stroke of state." The phrase did not appear within an English text before the 19th century except when used in translation of a French source, there being no simple phrase in English to convey the contextualized idea of a "knockout blow to the existing administration within a state."

...
Wikipedia