Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

Tarquĭtĭus, ii, m., an Etruscan proper name; so esp. the Etruscan Tarquitius, who wrote on divination, Macr. S. 3, 7, 2; Lact. 1, 10, 2; Plin. ind. libri 2.
Hence, Tar-quĭtĭānus, a, um, adj., of Tarquitius: libri, Amm. 25, 2, 7.