Let the cat out of the bag


The saying means to reveal a secret or disclose facts that were previously hidden. It can also be used to refer to someone who is a ‘blabbermouth’ and provides quite the visual – a cat, playing the part of the secret, coming out of the bag which plays the role of where the secret was hiding. The first recorded use of this phrase comes from a book review in a 1760 edition of London Magazine, where the reviewer wished the author had not spoiled a surprise or secret in the book.