(Παγασαῖος), i. e. the Pagasaean, from Pegasus, or Pegasae, a town in Thessaly, is a surname of Apollo, who there had a sanctuary said to have been built by Trophonius (Hes. Scut. Herc. 70, with the Schol.), and of lason, because the ship Argo was said to have been built at Pagasus. (Ov. Het. 7.1, Her. 16.345.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890