All 3 Uses

coup
in
Mao’s Last Dancer
(Edited)

The most nerve-racking speculation was that there were factions of the military loyal to Lin Biao who could be attempting a coup to topple Mao's government.
Chpt 1.6

coup = sudden overthrow of a government by use of limited force
Lin Biao had been planning a major coup for a number of years, and Chairman Mao had narrowly escaped several assassination attempts.
Chpt 1.6 *
"Jeano, is it true that Mary McKendry is coming?" I asked our general manager eagerly.
"Yes, a real coup," he replied, beaming.
Chpt 3.26 *

coup = brilliant and notable success

Definitions:

(1) (coup as in: deposed in the coup)
the sudden overthrow of a government by use of limited force

This sense of coup is also called a coup d'état.
(2) (coup as in: a financial coup)
a brilliant and notable success

The term "coup de theatre" indicates a sensational moment in a theatrical stagecraft -- typically a surprise; or possibly a highly successful theatrical production.
(3) (coup de grace as in: delivered the coup de grace)
deathblow

(literally a sword strike that mercifully kills a wounded animal, or metaphorically as the last in a series of things that defeated an opponent, idea, business or other entity.)

The term coup de grace indicates a merciful death blow.
(4) (meaning too rare to warrant focus)