Etymology

Late 17th century. Borrowing from French coup de grâce ‎(“finishing blow”). Originally referring to a merciful stroke putting a fatally wounded person out of misery or to the shot delivered to the head of a prisoner after facing a firing squad.

Pronunciation

• IPA^(key): /ku də ɡrɑs/
• IPA^(key): /ku də ɡrɑː/ (hyperforeign)—Some English speakers, aware that some final consonants are dropped in French, overcompensate by dropping the final /s/ sound in grâce, making this sound like French coup de gras (“strike of grease”). This mispronunciation is quickly becoming ubiquitous and is being popularized by the media (e.g., it occurs twice in Quentin Tarantino's Kill Bill Volume 2).
• Rhymes: -ɑːs