“Let the cat out of the bag” is the phrase for accidentally revealing a secret. Here is what it means, where it comes from, how to use it, and a few sayings that share its idea.
What Does “Let the Cat Out of the Bag” Mean?
The phrase means to reveal a secret — usually by accident or carelessness, and often before the right moment. Once the cat is out of the bag, it cannot be put back: the secret is known and there is no undoing it. It is most often used about a surprise spoiled or a confidence let slip, as when someone mentions a surprise party in front of the guest of honour.
Origin of the Proverb
The phrase dates from the eighteenth century, and two colourful theories compete to explain it. The most popular links it to a market swindle: a dishonest trader would sell what looked like a piglet tied up in a bag, but had secretly put a worthless cat inside — the trick was exposed only when the buyer got home and “let the cat out of the bag” (this is also the root of “a pig in a poke”). A second theory points to the “cat o’ nine tails,” the naval whip kept in a bag and taken out for a flogging. Neither is firmly proven, but both make the meaning of an unwelcome revelation wonderfully vivid.
Examples in a Sentence
- “It was meant to be a surprise, but Grandpa let the cat out of the bag.”
- “Don’t let the cat out of the bag about the engagement just yet.”
- “She let the cat out of the bag about the merger before it was announced.”
Similar Proverbs
- To spill the beans — to give away a secret.
- A word once spoken cannot be recalled — what is said cannot be unsaid.
- Loose lips sink ships — careless talk can do great harm.
- A secret between two is God’s secret; between three, all men’s — secrets rarely stay secret.
For more sayings about secrets and speech, see our smart thoughts and the full library of proverbs and their meanings.
Frequently Asked Questions
What does “let the cat out of the bag” mean?
It means to reveal a secret, usually by accident and often before the right time.
Where does the phrase come from?
It dates from the 1700s. The popular theory ties it to a market trick of selling a cat in a bag as a piglet; another points to the naval “cat o’ nine tails” whip kept in a bag. Neither is firmly proven.
What is a similar saying?
“To spill the beans” means the same thing — to give away a secret you were meant to keep.