Wiktionary
modchip
n. A computer chip or similar hardware device used to modify the behaviour of a games console.
Wikipedia
Modchip
A modchip (short for modification chip) is a small electronic device used to alter or disable artificial restrictions of computers or entertainment devices. Modchips are mainly used in videogame consoles, but also in some DVD or Blu-ray players. They introduce various modifications to its host system's function, including the circumvention of region coding, digital rights management, and copy protection checks for the purpose of using media intended for other markets, copied media, or unlicensed third-party ( homebrew) software.