Bythos
From Theosopedia
(Gk.). A Gnostic term for one of the primordial states of the cosmos. It means “Depth” and is the source of the manifested universe. It is equivalent to Primordial Space or Akasa.
Helena P. BLAVATSKY equates it with the second LOGOS. (SD I:349).
Blavatsky mentions Bythos again, stating, “In the ‘Book of Numbers’ it is explained that EN (or Ain, Aiôr) is the only self-existent, whereas its ‘Depth’ (Bythos or Buthon of the Gnostics, called Propator) is only periodical. The latter is Brahma as differentiated from Brahma or Parabrahm” (SD I:214). See BRAHMA.
P.S.H.