Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Linternum, i, v. Liternum.
Līternum (Lint-), i, n., a city of Campania, situated to the north of the mouth of the river Liternus, now the village of Patria, Mel. 2, 4, 9; Plin. 3, 5, 9, § 61; Liv. 22, 16; Ov. M. 15, 714; Sil. 6, 654; 8, 533.
Hence,