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Let the cat out of the bag

“Let the cat out of the bag” is a common English idiom that’s used to describe what happens when someone tells a secret.

Usually, if someone “lets the cat out of the bag,” the secret they’ve revealed has consequences. Perhaps someone revealed another’s surprise party, shared something personal about another person, or betrayed another’s confidence in a fundamental way. The idiom dates back to at least the 1500s and perhaps earlier. 

Let the cat out of the bag meaning


Meaning of “Let the cat out of the bag” 

“Let the cat out of the bag” is used as a way of describing when someone lets others in on a secret. It’s usually used when the secret-teller has done so without the other’s permission. For example, someone might use the phrase to refer to someone mistakenly telling another, or a group of people, something they weren’t supposed to. 


When To Use “Let the cat out of the bag” 

It’s possible to use “let the cat out of the bag” in a wide variety of situations. It could be used lightheartedly or more seriously depending on what’s being revealed. The phrase might also be used by the person telling the secret or someone describing what another did. For example, one person tells a secret they learned and the other listening replies in surprise that they can’t believe they “let the cat out of the bag.” 


Example Sentences With “Let the cat out of the bag” 

  • Don’t you dare let the cat out of the bag! We have to keep this a secret. 
  • Did you hear? Marcus let the cat out of the bag. What are we supposed to do now? 
  • I can’t believe he told them that, he really let the cat out of the bag. 
  • I hope no one lets the cat out of the bag, I really don’t want to mess this up. 
  • There’s only so much we can do now that he let the cat out of the bag. 


Why Do Writers Use “Let the cat out of the bag?” 

Writers use “let the cat out of the bag” in the same way and for the same reasons that it’s used in everyday conversation. It’s possible to work the phrase into a wide variety of different types of dialogue and include it as a way of referring to different situations. For example, a writer might use the phrase when one of their characters has revealed something to their companions that they weren’t supposed to. This idiom is quite old and well-used so it should be noted that it’s not always going to be effective as it might’ve been in the past. Most readers will likely read “let the cat out of the bag” as a cliche. 


Origins of “Let the cat out of the bag” 

Like many idioms, “let the cat out of the bag” does not have a clear origin. It evolved over time with various possible derivations. One of the earliest reported uses of the phrase is in a letter to Martin Luther, the figure most closely associated with the Reformation, from Johannes Agricola, one of his followers. It dates to 1530.

In contrast to the previous date, some suggest that the phrase relates to a torture implement known as the cat o’nine tails that was used on Royal Navy vessels. It was often shortened to just “the cat” and was a multi-tailed fail used to flog those who stepped out of line. The name was first used in 1681 in the reports of a London murder. When it was used, reportedly, it was carried out in a red sack. The phrase might’ve evolved from the act of “letting the cat out of the bag,” especially applicable to the instances in which one sailor revealed the misdeeds of another. 

Another possible origin comes from the “pig in a poke” scam in which a customer would be sold a bag supposedly containing a suckling pig but when they opened it there would be a cat inside, a much less valuable purchase. 


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