Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Castricius or -tius, a, um, a Roman gentile name, Cic. Verr. 2, 3, 80, § 185; id. Fl. 23, 54; id. Att. 12, 28, 3 al.
Hence, Castriciānus or -tiānus, a, um, adj., pertaining to a Castricius: negotium, Cic. Att. 12, 28, 3: nomen, id. Fl. 23, 24: mendum, id. Att. 2, 7, 5.