Spiritually, the pyramid is a symbol of integration of the Self and the Soul. In dreams it can represent death, but also indicates rebirth. It is a guardian of power.
Psychological / Emotional Perspective:
The pyramid always signifies a wider awareness of power and energy. There is a point inside the pyramid where all the planes intersect. This will regenerate any matter that is placed there, for instance razor blades will become sharp again. In a larger pyramid, that particular spot can be used for enhancing mystical experiences. In dreams, to enter a pyramid is to be searching for the meaning of life.
Everyday Material Aspects:
A pyramid is a very powerful image. On a physical level, it is a building of wonder. On a mental level, it is a structure of regeneration. It will depend on our level of awareness as to which interpretation is valid.