Eleusinian

It was sound as séance, Eleusinian hallucinations of watching Jerry Garcia back Pharoah Sanders, kicking stardust grooves snatched from primordial savanna rituals.
Darkside returns to lay claim to the title of best psychedelic rock band in the world|Jeff Weiss|July 23, 2021|Washington Post
The pig was the animal usually offered to Demeter, the goddess of the Eleusinian mysteries.
Myth, Ritual, and Religion, Vol. 1|Andrew Lang
In the Eleusinian mysteries the rape of Persephone by Pluto, the winter god, is portrayed.
The Sex Worship and Symbolism of Primitive Races|Sanger Brown, II
In memory of her sorrows Demeter establishes the Eleusinian mysteries (which, however, were purely agrarian in origin).
Hesiod, The Homeric Hymns, and Homerica|Homer and Hesiod

He has been blamed for thus exposing the Eleusinian mysteries of literature to the uninitiated.
Curiosities of Literature, Vol. 1 (of 3)|Isaac D'Israeli
The Orphic, chiefly deserving mention as the probable foundation of the Eleusinian.
Mysticism and its Results|John Delafield