gallicism

noun

1. a French idiom or expression used in another language, as Je ne sais quoi when used in English.
2. a feature that is characteristic of or peculiar to the French language.
3. a custom or trait considered to be characteristically French.

noun

1. a word or idiom borrowed from French

n.

“French word or idiom,” 1650s, from Gallic + -ism.