Definitions of cartridge:

• noun:   ammunition consisting of a cylindrical casing containing an explosive charge and a bullet; fired from a rifle or handgun
• noun:   an electro-acoustic transducer that is the part of the arm of a record player that holds the needle and that is removable
• noun:   a module designed to be inserted into a larger piece of equipment

  Example: "He loaded a cartridge of fresh tape into the tape deck"

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