slang A handgun. The term originated as a trademark for a specific pistol made by Austrian gun manufacturer Gaston Glock. Watch out, I bet that guy has a glock on him.
glock
n. a gun; a revolver. (Generalized from Glock, the name of an Austrian manufacturer of semiautomatic pistols. Generic and inexact in this sense.) Sam was carrying a glock and threatened to end the argument his own way.