Lewis & Short

dĭācŏnĭcus, a, um, adj. [diaconus], belonging to a deaconship: loca, Cod. Th. 16, 5, 30.
Subst.: dĭācŏnĭcum, i, n., a place for storing the vessets of the altar, Cod. Theod. 16, 5, 10.