AnimaMundi (Lat.). The“Soul of the World”, the same as the Alaya of the Northern Buddhists; the divine essence which permeates, animates and informs all, from the smallest atom of matter to man and god. It is in a sense the “seven-skinned mother” of the stanzas in the Secret Doctrine, the essence of seven planes of sentience, consciousness and differentiation, moral and physical. In its highest aspect it is Nirvâna, in its lowest Astral Light. It was feminine with the Gnostics, the early Christians and the Nazarenes; bisexual with other sects, who considered it only in its four lower planes. Of igneous, ethereal nature in the objective world of form (and then ether), and divine and spiritual in its three higher planes. When it is said that every human soul was born by detaching itself from the Anima Mundi, it means, esoterically, that our higher Egos are of an essence identical with It, which is a radiation of the ever unknown Universal ABSOLUTE.
Source: H.P.Blavatsky - The Theosophical Glossary