Exploring the Curiosities 8 Hidden Histories Behind Common Phrases and Idioms

5. Let the Cat Out of the Bag

To "let the cat out of the bag" means to reveal a secret, often unintentionally. This phrase harks back to medieval marketplaces, where unscrupulous vendors would substitute a cat for a piglet in a sack, deceiving buyers. Once the sack was opened, the cat would escape, revealing the fraud. This practice led to the idiom, which captures the moment of unveiling a hidden truth or secret, often leading to surprise or embarrassment. The phrase serves as a cautionary tale about deception and the inevitability of truth coming to light.