The foundation of something such as a belief or way of life is the things on which it is based.

The foundations of a building or other structure are the layer of bricks or concrete below the ground that it is built on.

A foundation is an organization which provides money for a special purpose such as research or charity.

If a story, idea, or argument has no foundation, there are no facts to prove that it is true.

Foundation is a skin-coloured cream that you put on your face before putting on the rest of your make-up.