ἐμμυστήριος

From LSJ

ὤδινεν ὄρος, Ζεὺς δ' ἐφοβεῖτο, τὸ δ' ἔτεκεν μῦν → the mountain was in laboreven Zeus was afraid — but gave birth to a mouse

Source

Spanish (DGE)

-ον
místico, relativo al misterio τύπος προσευχῆς Gr.Naz.M.36.725A.