Cartridge
From Sega Retro
A cartridge is a plastic case which houses the ROM chip that stores a game's data, and in some cases also contains additional hardware such as the CR2032 SRAM. Some examples of cartridge-based systems include the Sega Mega Drive / Genesis, Sega Master System and Sega Game Gear.
For details of cartridges on Sega consoles, see:
References