or Pyrrhos. Son of Achilles; called Pyrrhos from his yellow hair, and Neoptolemos because he was a new soldier, or one that came late to the siege of Troy. According to Virgil, it was this young man that slew the aged Priam. On his return home he was murdered by Orestes, at Delphi.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894