Frenchism
/ˈfrɛn(t)ʃɪz(ə)m/noun
1A French idiom or form of expression.
2(A partiality for) French character, style, or customs; an instance of this.
Origin
Mid 18th century; earliest use found in Horace Walpole (1717–1797), author, politician, and patron of the arts. From French + -ism.