Adjective
Pertaining to Eleusis, in Greece, or to secret rites in honor of Ceres, there celebrated; as, Eleusinian mysteries or festivals.
Source: Webster's dictionaryBenko, Stephen, The virgin goddess: studies in the pagan and Christian roots of mariology, BRILL, 2004, note 111 on pp. 63 - 4, and p. 175. Her Eleusinian mysteries were open to initiates of any gender or social class. Source: Internet
Because of this association, Hecate was one of the chief goddesses of the Eleusinian Mysteries, alongside Demeter and Persephone. Source: Internet
Burkert, op.cit. Ch.4 Indirect evidence in support of the entheogenic theory is that in 415 BC Athenian aristocrat Alcibiades was condemned partly because he took part in an "Eleusinian mystery" in a private house. Source: Internet
Julian attempted to restore the Eleusinian Mysteries and was the last emperor to be initiated into them. citation The Roman emperor Theodosius I closed the sanctuaries by decree about 30 years later, in 392 AD. Source: Internet
In the Eleusinian mysteries her return is the symbol of immortality and hence she was frequently represented on sarcophagi. Source: Internet
Nilsson (1940), p. 50: "The Demophon story in Eleusis is based on an older folk-tale motif which has nothing to do with the Eleusinian Cult. Source: Internet