(adj.adv.) = μυστικός: mystĭcus, a, um, adj.
* Of or belonging to secret rites or mysteries, mystic, mystical (poet.): mystica sacra Dindymenes,Mart. 8, 81, 1: vannus Iacchi,Verg. G. 1, 166: vitis,Tib. 3, 6, 1: lampas,Stat. Th. 8, 765.—In plur. subst.: mystĭ-ca, ōrum, n., things pertaining to secret rites, Lampr. Alex. Sev. 26; Inscr. Orell. 2353.—Hence, adv.: mystĭcē, mystically (post-class.), Sol. 32; Ambros. in Luc. 7, § 9.

s. TLL