Choose the correct meaning of the given idiom.

A skeleton in the cupboard

An embarrassing fact to be kept secret

The correct meaning of the idiom "a skeleton in the cupboard" is an embarrassing fact to be kept secret.

It is a metaphor for a secret that someone is ashamed of and wants to keep hidden. The idiom is often used to describe secrets that are personal or family secrets, but it can also be used to describe secrets that are related to a person's career or public life.

The other options are incorrect:

• A popular fact which is not hidden: This is not the meaning of the idiom "a skeleton in the cupboard."
• A popular fact to be kept secret: This is not the meaning of the idiom "a skeleton in the cupboard."
• An embarrassing fact not to be kept secret: This is not the meaning of the idiom "a skeleton in the cupboard."