Meaning

noun ammunition consisting of a cylindrical casing containing an explosive charge and a bullet; fired from a rifle or handgun

noun a light-tight supply chamber holding the film and supplying it for exposure as required

noun a module designed to be inserted into a larger piece of equipment

originCorruption of earlier cartage, from French cartouche, from Italian cartoccio (“roll of paper”), from Medieval Latin carta (“paper”). Doublet of cartouche.

Etymology from Wiktionary, CC BY-SA 3.0