“Hear it through the grapevine” means to learn information indirectly, usually from other people rather than from the person or organization involved.
Today, people use it for unofficial news, workplace gossip, family updates, or community rumors. The phrase often suggests that the information may be true, but it did not come from a direct or formal source.
The expression is usually linked to the United States in the Civil War era. Informal communication networks spread news quickly and unpredictably, and people compared those twisting routes to a grapevine. That image helped the phrase come to mean news passed from person to person.
- I heard through the grapevine that our teacher is moving to another school.
- She heard through the grapevine that the company will open a new office.
You would not usually use this phrase for information you got in an official email, announcement, or conversation with the source. In that case, you heard it directly. The phrase works best when the path of the information is informal and a little uncertain.