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.

Firmĭānus, a, um, v. Firmius.

Firmĭus, ii, m., a Roman proper name, e. g. Firmius Catus, Tac. A. 2, 27; 4, 31.
Hence, Firmĭānus, a, um, adj., of Firmius, an unknown silver-worker of that name: Firmiana vasa, Plin. 33, 11, 49, § 139 (Jan. Furniana).