A "gentleman bandit" --- i.e., one who is super-courteous and tips his fedora when committing his crimes.
At da end of "Tom Sawyer", Tom tells Huck about how robbers are da ultimate "doffenders" --- "Robbers are the most polite folks in the world, especially to the women --- they always take off their hats and talk polite."
by QuacksO February 18, 2023