Frenchism

Century Dictionary and Cyclopedia

1. n. A custom, usage, or idiom peculiar to or characteristic of France or the French; a Gallicism.

Wiktionary

1. n. A custom peculiar to France.
2. n. A word, phrase or linguistic feature typical of French.

GNU Webster's 1913

1. n. A French mode or characteristic; an idiom peculiar to the French language.