The term "quid" is a colloquial slang used in the United Kingdom to refer to the British Pound Sterling (£). Its origins may trace back to Quidhampton, a village in Wiltshire, England, where a Royal Mint paper mill was once located. It's possible that any paper money produced in this mill could have been colloquially referred to as a "quid." Despite its informal nature, the pound sterling has a rich history, dating back more than 12 centuries, making it the world's oldest currency still in use. Today, "quid" is widely used in everyday conversation and informal writing to represent the pound, but it is not used in formal financial contexts or official documentation.