Buthos or Bythos
Buthos Or Bythos (Βύθος, the abyss) was the primal essence, among the Valentinian Gnostics, where the spirit is lost in contemplation. According to this system all existence has its ground in the self-limitation of the Buthos, which has in it a fulness of divine life that flows out in the complete series of ceons (q.v.). -Gardner, Faiths of the World, s.v. SEE GNOSTICS.