Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Hyllus (Hȳlus), i, m., = Ὕλλος or Ὕλος, a son of Hercules by Dejanira, and husband of Iole, Ov. H. 9, 44; id. M. 9, 279; Stat. Th. 8, 508.