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Mattĭăcus, a, um, adj., of or belonging to Mattiacum (the mod. Wiesbaden): Mattiaci fontes, the warm mineral springs of Wiesbaden, Plin. 31, 2, 17, § 20: aquae, Amm. 29, 4, 3: pilae, soap-balls for coloring the hair, Mart. 14, 27: ager, Tac. A. 11, 20.
In plur. subst.: Mattĭăci, ōrum, m., the inhabitants of Mattiacum, Tac. G. 29; id. H. 4, 37.