Egregores. Eliphas Lévi calls them “the chiefs of the souls who are the spirits of energy and action” ; whatever that may or may not mean. The Oriental Occultists describe the Egregores as Beings whose bodies and essence is a tissue of the so-called astral light. They are the shadows of the higher Planetary Spirits whose bodies are of the essence of the higher divine light.
Source: H.P.Blavatsky - The Theosophical Glossary