Pīrĭthŏus, i, m., = Πειρίθοος,
son of Ixion , king of the Lapithae , husband of Hippodamia , and friend of Theseus. After the death of Hippodamia , he descended , in company with Theseus , to the infernal regions , to carry away Proserpine; but was , together with Theseus , seized and detained in chains. Theseus was afterwards delivered by Hercules , who vainly endeavored to save Pirithoüs also ,