All 4 Uses

coup
in
How the Garcia Girls Lost Their Accents
(Edited)

It was a coup for the youngest daughter to have gathered the scattered family in the Midwest for a weekend.
Chpt 1.2

coup = notable achievement
But the real coup was how Sofia had managed to have the husbands included this year.
Chpt 1.2
But the coup the youngest daughter most wanted was to reconcile with her father in a big way.
Chpt 1.2 *
But tonight, as we've agreed, we're staging a coup on the same Avenida where a decade ago the dictator was cornered and wounded on his way to a tryst with his mistress.
Chpt 2.6 *

coup = a sudden overthrow of a government by use of limited force

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)