Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Pentheus, ĕi and ĕos, m., = Πενθεύς, son of Echion and Agave, grandson of Cadmus, and king of Thebes; having treated with contempt the rites of Bacchus, he was torn in pieces by his mother and her sisters when under the influence of the god, Ov. M. 3, 514; Prop. 3, 17 (4, 16), 24; 3 (4), 22, 33; Ov. Tr. 5, 3, 40; Hor. Ep. 1, 16, 73; id. C. 2, 19, 14.
Hence,