Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Tyras, ae, m., = Τύρας, a river in Sarmatia, now the Dniester, Mel. 2, 1, 7; Ov. P. 4, 10, 50.
Called also Tyra, Plin. 4, 12, 26. § 82.