However when I came across it again in THE MYSTERY OF THE BLUE TRAIN I just felt I had to document it.
At the beginning of chapter 2
On turning a corner he came upon a scene of some activity....
"Something has been happening, yes?"
"Mais oui, Monsieur. Two apaches set upon an elderly American gentleman."
Then in chapter 4, the American gentleman is talking to his daughter
"Nothing to tell Ruthie. Some apache fellows got a bit fresh and I shot at them and they got off. That's all."
Apparently the word came into use 1915-20 via French
n. pl. a·paches (ə-pāsh', ä-päsh')
- A member of the Parisian underworld.
- A thug; a ruffian.
Have you come across similar words in your reading?