GHZ or GHz may refer to: Chabab Ghazieh SC, a Lebanese association football club Gigahertz (GHz), unit of frequency Greenberger–Horne–Zeilinger state, a specific entangled quantum state of three or more particles GHZ experiment, an experiment associated with such a state Galactic Habitable Zone, the region of a galaxy that is favorable to the formation of life Green Hill Zone, the first level in Sonic the Hedgehog