Bilibin was now at army headquarters in a diplomatic capacity, and though he wrote in French and used French jests and French idioms, he described the whole campaign with a fearless self-censure and self-derision genuinely Russian.
There are no more uses of "idiom" in the book.
Show samples from other sources
I said, using one of my favorite Siaru idioms.
Patrick Rothfuss -- The Name of the Wind
The words he uses are the idioms of popular songs and poems in the newspaper.