(by extension) A prefabricated subassembly that can be easily installed in or removed from a larger mechanism or replaced with another interchangeable subassembly.
(computing) A vessel which contains the ink or toner for a computer printer and can be easily replaced with another.
(computing) Magnetic tape storage, used for storing (backup) copies of data.
(obsolete) A small paper package, e.g. in an old book about making printer's type: After all the type has been cast: "The Boy will paper up each sort in a cartridge by itself".