Coo?

Hello,
I am not exactly sure how to spell or ask this, but there is a phrase or word that I really want to find the origin and meaning of. I will do my best to spell it as it sounds. The word is "coo de graw", this is how it sounds. Any help would be appreciated.

Thanks !!
Eric

From dictionary.com:

coup de grâce P Pronunciation Key (koo du gräs)
n. pl. coups de grâce
1. A deathblow delivered to end the misery of a mortally wounded victim.
2. A finishing stroke or decisive event.

[French : coup, stroke + de, of + grâce, mercy.]