French word chien comes from Proto-Indo-European *ḱwṓ (Dog.)
*ḱwṓ (Proto-Indo-European)
Dog.
*kō (Proto-Italic)
*ḱwn-i- (Proto-Indo-European)
canes (Latin)
canis (Latin)
A dog (animal). A dog (foul person).
chien (Old French)
Dog (animal).
chien (Middle French)
chien (French)
Cock, hammer (of a firearm). Dog.