The word "derringer" is usually used to describe a small hideout pistol, usually a single or double barrel, popularized in the mid to late 19th century among gamblers and outlaws. It is a misspelling of the last name of Henry Deringer, who designed and built small, single shot muzzleloading pocket pistols. Henry Deringer produced his first pocket pistols as early as 1852, and sold them under a company carrying his own name. As the popularity of these small backup weapons grew, other companies began producing their own pocket models, from big names such as Colt and Remington, on down to smaller businesses lost to time, but the name "Derringer" became synonymous with all small, single shot or multi barreled pocket pistols, even if they weren't made by the actual Deringer Company.
The derringer pistol has been made in numerous calibers from .22 Long Rifle all the way up to some of the larger calibers such as .45 Long Colt or .357 Magnum. Longer barreled versions in .45LC can also accept .410 gauge shotshells. There are numerous manufacturers of derringer-style pistols today, among them Bond Arms, Cobray Enterprises, and American Derringer Company.
The derringer pistol earned it's fame and infamy as being the weapon of choice for gamblers or other men of ill repute, as a woman's personal protection piece stuck in a stocking, but most famously as the weapon of choice for assassin John Wilkes Boothe, who used a .44 caliber muzzleloading percussion derringer to kill President Abraham Lincoln in Ford's Theatre during a play.