pistol (n.) Look up pistol at Dictionary.com
"small hand-held firearm," 1570s, from Middle French pistole "short firearm" (1566), of uncertain origin, sometimes said to be from German Pistole, from Czech pis'tala "firearm," literally "tube, pipe," from pisteti "to whistle," of imitative origin, related to Russian pischal "shepherd's pipe."

But earlier English form pistolet (1550) is said to be from Middle French pistolet "a small firearm," also "a small dagger," which may be the literal sense; though some connect this word with Italian pistolese, in reference to Pistoia, town in Tuscany noted for gunsmithing. Pistol-whip (v.) is first recorded 1942.