Concept used by Carl Jung in regards to the theory of the Collective Unconscious. An archetype is a universal symbol or icon that exists in all humans at birth and will be recognized once any human sees it. Jung spent a lot of his life searching for such architypes that were common to different cultures which had no contact with one another. They manifest themselves in dreams, myths, and art.
It is also a popular name for architecture firms...
Source:
http://www.cgjungpage.org/articles/rutzky1.html
http://www.mentalstates.net/add_g.html