Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Phŏrōneus (trisyll.), ĕi and ĕos, m., = Φορωνεύς, son of Inachus, king of Argos, and brother of Io, Hyg. Fab. 124; 143; 225; 274; Plin. 7, 56, 57, § 193; Stat. Th. 4, 889.
Hence,