Акаша
[Sanskrit, from the root kās “to be visible, appear,” “to shine brightly,” “to see clearly”] An etheric substance and dimension. Primary substance, the subtlest, ethereal essence, which fills the whole of space. Akasha refers to the “etheric” energy vibrating at a certain frequency so as to absorb, or record, all of the impressions of life.
See also
Sources
Mark L. Prophet and Elizabeth Clare Prophet, Saint Germain On Alchemy: Formulas for Self-Transformation