arcanum
From LSJ
ἅπαντι δαίμων ἀνδρὶ συμπαρίσταται εὐθὺς γενομένῳ μυσταγωγὸς τοῦ βίου → a spirit assists every man from birth to be the leader of his life
Latin > French (Gaffiot 2016)
(1) arcānum,¹¹ ī, n. (arcanus), secret : Hor. O. 1, 18, 16 ; Ov. M. 7, 192, etc.
Latin > English
arcanum arcani N N :: secret, mystery; secret/hidden place