United Auto Workers President Shawn Fain wears a shirt reading 'Trump is a Scab' at the Democratic National Convention on Aug. 19, 2024.

Over its long history, the American labor movement has displayed a remarkably rich vocabulary for shaming those deemed traitors to its cause.

Some insults, such as “blackleg,” are largely forgotten today. Others, such as “stool pigeon,” now sound more like the dated banter of film noir. A few terms still offer interesting windows into the past: “Fink,” for example, was used to disparage workers who informed for management; it seems to have been derived from “Pinkerton,” the private detective agency notorious for strikebreaking during mass actions like the Great Railroad Strike of 1877.

Originally published on theconversation.com, part of the BLOX Digital Content Exchange.