What is "keltos"

In Greek mythology, Keltos or Celtus (; , ) was regarded as the eponymous founder of the Celts.

There are two alternative traditions. One, found in Appian's Illyrian Wars, holds that Keltos was the son of Polyphemos and Galatea and the brother of Illyrius and Galas. The other, found in the Erotica Pathemata ("Sorrows of Love") by the 1st century grammarian Parthenius of Nicaea, and also known from the medieval Etymologicum Magnum, has Keltos as the son of Heracles and Keltine.