Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Pūcīnum, i, n., = Πούκινον, a town in Illyria, now Proseck, Plin. 3, 18, 22, § 127.
Hence, Pūcīnus, a, um, adj., of or belonging to Pucinum: vinum, Plin. 14, 6, 8, § 60.