The Beginnings of 12 Everyday Expressions You Use Without Knowing Why

"Let the Cat Out of the Bag" — Market Deceptions and Revelations

The phrase "let the cat out of the bag" is used to describe the act of revealing a secret, often unintentionally. Its origins are believed to stem from medieval markets, where unscrupulous vendors would substitute a cat for a piglet in a sack, deceiving buyers. When the buyer opened the sack and the cat was revealed, the deception was exposed, giving rise to the expression. This idiom highlights the themes of deception and revelation, capturing the human fascination with secrets and their eventual exposure. As commerce evolved and markets became more regulated, the phrase "let the cat out of the bag" transitioned into a metaphor for uncovering hidden truths. Its enduring popularity reflects the universal human experience of dealing with secrets and the consequences of their revelation.