"Leak" is word used by Kilgore Trout, a character from many Kurt Vonnegut novels, to mean mirror. Mr. Kilgore Trout, was a science fiction writer who, like most science fiction writers, hadn't the slightest bit of interest in technical details. But he did have a wild imagination of other planets, alien civilizations and alternate universes. His imagination led him to speculate that mirrors were really weaknesses in the barrier between alternate or parallel universes, hence "leak." When someone in Kilgore Trout's presence would express their need to urinate by saying "I have to take a leak," he would respond "where I come from that would mean you are planning to steal a mirror."