From dictionary.com: "the original pattern or model from which all things of the same kind are copied or on which they are based; a model or first form; prototype."
In Kabbalah, the blueprint or original image from which creation emerges; related to the the first of the four worlds: Atziluth.
"Concept and word are one and the same substance. The concept is internal and the word is external. This process is similar in all the levels of consciousness and in all dimensions of space. Ideas are only abstract concepts. Ideas are much larger concepts and belong to the world of Spiritual Archetypes. Every existing thing in the physical world is a copy of those archetypes. During Samadhi, the initiate can visit the world of spiritual archetypes in Astral or Super-astral journeys." - Samael Aun Weor, The Perfect Matrimony
"Sexual energy contains within it the living archetype of the authentic Solar Man, which must take shape within us." - Samael Aun Weor, The Mystery of the Golden Blossom