Tattler (noun)

A person who reveals secrets or private information to others.

Origin:

Origin unknown, first recorded in the late 17th century.

Examples:

1. She was known as a tattler, always willing to share others' secrets.
2. The tattler was not well-liked by her classmates, who felt she couldn't be trusted.
3. He was a tattler, always quick to reveal secrets to authority figures.
4. She was known as a tattler, and her friends never confided in her.
5. He was a tattler, and he was always getting people into trouble.