by Melissa
(5 Poseideon) Little is known about this festival. It appears to be related to the Proerosia festival, as the Ancient Greek dictionary (LSJ) says it is equivalent. The etymology of the name suggests it might be related to the Greek πληρότης (plerotes), or “fullness.” Whether the fullness of the festival indicates a feast or something about the fullness of the season or the grain jars is unclear.
The holiday further appears to be devoted to Zeus, according to Jony Mour. He includes it with Pandia and the Peloria as holidays devoted to Zeus and that it was celebrated in Athens on the 5th of Poseideon.
Sources:
<<Οι Γιορτές των Αρχαἰων Ελλήνων>> by Jony Mour; published by Academia,
https://www.academia.edu/4940897/4957853-Οι-Γιορτές-Των-Αρχαίων-Ελλήνων. Accessed December 3, 2019.
Liddle Scott and Jones, Greek–English Lexicon, online app.