This paper explores the term λευστήρ applied to Kleisthenes of Sikyon by the Pythia in Hdt. 5.67.2, first by exploring the poetics of stoning and pollution in Ancient Greece, then by arguing for the validity of both the more predictable meaning, 'stoner', and the Suda's sometimes contested gloss on the word, 'worthy of being stoned'. While the argument has been suggested before, sufficient linguistic evidence for understanding λευστήρ in this sense has not been presented in the past. The paper provides more conclusive evidence and also suggests that recent applications of the φαρµακός paradigm are inaccurate. ἐπεθύµησε ὁ Κλεισθένης ἐόντα Ἀργεῖον ἐκβαλεῖν ἐκ τῆς χώρης. ἐλθὼν δὲ ἐς ∆ελφοὺς ἐχρηστηριάζετο εἰ ἐκβάλοι τὸν Ἄδρηστον· ἡ δὲ Πυθίη οἱ χρᾷ φᾶσα Ἄδρηστον µὲν εἶναι Σικυωνίων βασιλέα, ἐκεῖνον δὲ λευστῆρα.Kleisthenes wanted to expel [Adrastos] from the land, since he was an Argive. He went to Delphi and consulted the oracle as to whether he should expel Adrastos, and the Pythia's response was that Adrastos was king of the Sicyonians, but that he, Kleisthenes, was a λευστήρ.