Gallicism is a noun that refers to a French expression adopted by speakers of another language.

Although it refers to The French language, Gallicism — like the French language itself — has its origin in Latin. The word refers to people descended from Gaul, a region that later became France. Here’s an example:

Lisa’s use of the phrase je ne sais quoi confused me a little before I realized it was a Gallicism. Here I was thinking my daughter had learned French when really she was just using a French term that is common among English speakers.