Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Bătāvus, a, um, adj., pertaining to Batavia, Batavian, of Holland, Dutch: spuma, Mart. 8, 33, 20.
Hence, Batāvi, ōrum, m., = Βατάουοι, Ptol., the Batavians, Hollanders, Dutch, Tac. H. 4, 12; id. G. 29 al.: Batavorum Insula, v. Batavia.
With penult scanned short: Vangiones Bătăvīque truces, etc., Luc. 1, 431.
Sing.: Bătā-vus, i, m., one of the Batavi, Mart. 14, 176.
Collectively, Juv. 8, 51; Sil. 3, 608.