Complex sentence: "Gong" is derived from the Old English "gang", which means "to go", and since the 11th century has been used to refer to a privy; a latrine or privy was the toilet of the Middle Ages.
Split into simpler sentences: Gong is derived from the Old English "gang", which means "to go", and since the 11th century has been used to refer to a privy. A latrine or privy was the toilet of the Middle Ages.