Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Hĕlĕnus, i, m., = Ἕλενος, son of Priam and Hecuba, a celebrated soothsayer, Cic. Div. 1, 40, 89; Verg. A. 3, 295; 329 sq.; Ov. M. 13, 99; Just. 17, 3.