The term
derringer is a genericized misspelling of the last name of
Henry Deringer, a famous 19th-century maker of small
pocket pistols. Many copies of the original Philadelphia Deringer pistol were made by other gun makers worldwide, and the name was often misspelled; this misspelling soon became an alternative generic term for any pocket pistol, along with the generic phrase
palm pistol Deringer's competitors invented and used in their advertising. The original Deringer pistol was a single-shot
muzzleloading pistol; with the advent of
cartridge firearms, pistols began to be produced in the modern form still known as a derringer.