black aspirin
n.— «“Don’t you do that in front of the doctor!” he ordered the unconscious man, and I have little doubt that he would have kicked him hard and often—in short, given him what used to be called in prison warders’ parlance “the black aspirin,” which is to say the prison warder’s boot—if I had turned my back for an instant.» —“The Evils of Ideology” by Theodore Dalrymple FrontPage Mag. Sept. 6, 2006. (source: Double-Tongued Dictionary)