foundation

noun:the lowest load-bearing part of a building, typically below ground level
- The engineers inspected the foundation of the old house for cracks.
noun:an underlying basis or principle for something
- Trust is the foundation of a strong relationship.
noun:an organization established to support a particular cause or activity
- Foundations often provide funding for educational programs.
noun:a cream or powder used as a base for facial makeup
- She applied a light layer of foundation before makeup.