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.

cassĭtĕrum (-ron), i, n., = κασσίτερος, orig. a mixture or alloy of lead, silver, and other metals; afterwards tin (= plumbum album), Plin. 34, 16, 47, § 156; Avien. Or. Mar. 260; cf. Charis. p. 21 P.; Diom. p. 315 ib.
Hence, cassĭtĕrĭnus, a, um, adj., = κασσιτέρινος, made of tin: lamella, Pelagon. Vet. 7.