Thompson submachine guns are also known as Tommy guns. They were popularized by gangsters and police officers in the early 20th century, earning the nickname "Chicago typewriter." The term "submachine gun" is often used synonymously with "machine pistol" or "automatic rifle." Other common synonyms for Thompson submachine guns include "trench broom," "chopper," "Chicago piano," and "street sweeper." These firearms were widely used in the military during World War II, and have become iconic in popular culture through their portrayal in films, television shows, and video games. Despite their association with violence and criminal activity, they remain an important part of firearms history and innovation.