(Πύθιος), the Pythian, from Pytho, the ancient name of Delphi, often occurs as a surname of Apollo, whose oracle was at Delphi. (Hom. Hymn. in Apoll. 373; Aeschyl. Agam. 521 ; Hor. Carm. 1.16. 6; Tac. Hist. 4.83.)
[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