TIL "deadline" originally meant a literal line around a Civil War prison camp that guards would shoot you for crossing

At Andersonville and other Civil War prison camps, the "dead line" was a boundary a short distance inside the stockade wall, and prisoners who stepped over it could be shot. Printers later borrowed the word for a guide line on a press, and only in the 20th century did it settle into the journalism and office meaning we use now. Kind of grim to remember that every time a manager says the deadline is Friday. Any other everyday words with surprisingly dark origins?