mĕsŏnyctĭus, a, um, adj., μεσονύκτιος, of midnight: afflatus, Isid. 5, 30, 4. Hence, subst.: † mĕsŏnyctĭum, ii, n., = μεσονύκτιον, midnight (post-class.): CVIVS MESONYCTIVM FACTVM EST V. ID. DEC., i. e. midnight apparition, Inscr. Mur. 333.