Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
2. Dŭrĭus, ii, m. (Dūrĭa, ae, m., Claud. in Laud. Ser. Reg. 72), one of the principal rivers of Spain, now the Douro, Mel. 3, 1, 7 sq.; Plin. 4, 20, 34, § 112 sq.; Sil. 1, 234 al.