1. An organization or institution established by endowment which provides funds for a particular purpose such as research or charity.The aims of Bill & Melinda Gates Foundation are, globally, to enhance healthcare and reduce extreme poverty, and in the United States, to expand educational opportunities and access to information technology.
2. The act of founding, establishing an institution or organization.She has been teaching since the foundation of the school.
3. An underlying basis, or support or principle for something.Her charges are completely without foundation.
4. The supporting layer of a building below the ground.