Pistol

Pistol is a small firearm designed for one-hand use. According to one theory, pistols owe their name to Pistoia, Italy, where handguns were made as early as the late 15th century.
It is a handgun whose chamber is integral to the barrel.

Sources:

Britannica. Pistol. Encyclopedia Britannica. Retrieved from: https://www.britannica.com/technology/pistol-weapon

Pistol. Merriam-Webster.com dictionary. Retrieved from https://www.merriam-webster.com/dictionary/pistol