Let the cat out of the bag

Meaning

To reveal a secret, usually by accident or earlier than intended.

Usage

Used for spoiled surprises, leaked plans, or private information becoming public. The tone can be playful or critical depending on context.

Origin & History

Origins and dates here are approximate summaries. Many idioms have disputed or unknown origins, and not every date has been checked against a historical dictionary, so treat specific dates and stories as a starting point rather than a citation.

Often explained through old market fraud stories where a seller substituted a cat for a piglet in a bag. The origin is plausible but not certain.

The phrase is associated with English rural and market imagery and became widely used for accidental disclosure by the 18th and 19th centuries.