Matianus
Could not find Matianum in Logeion dictionaries.
Matianum proper-name adjective neuter vocative singular, proper-name adjective masculine genitive plural, proper-name adjective masculine accusative singular, proper-name adjective neuter genitive plural, proper-name adjective neuter nominative singular, proper-name adjective neuter accusative singular of Matianus
Mātiānus, a, um, s. Mātius.
Mătĭānus, (16) a, um, de Matius : Suet. Dom. 21.