Πέρσαι

From LSJ

εἰς τὴν ἀγορὰν χειροτονεῖτε τοὺς ταξιάρχους καὶ τοὺς φυλάρχους, οὐκ ἐπὶ τὸν πόλεμον → you elect taxiarchs and phylarchs for the marketplace not for war

Source

English

Persae

Russian (Dvoretsky)

Πέρσαι: οἱ pl. к Πέρσης II.

Frisk Etymological English

Grammatical information: pl. (sg. rare)
Meaning: name of an Iranian people (The name Πέρσης of the brother of Hesiodos may have been reshaped after this.)
Derivatives: Περσικός in ἡ Περσική Persia, -αι a kind of women's slippers (Ar.), περσική peach (a loan from Christian imes) with περσικών orchard of peaches; περσικὰ καρύα the Persian (wal)nut, περσικός ὄρνις (Ar.) because the chicken was introduced in the time of the Median wars (but s. Taillardat, Images d' Aristophane $ 30. Περσίς (Aesch., Hdt.) a Persian soman; Περσίζω speak Persian (X.), adv. περσιστί (Hdt., X.).
Origin: LW [a loanword which is (probably) not of Pre-Greek origin] OP
Etymology: From OP Parsa. One assumed Πηρσ- > Περσ- (Meillet-Benvenist, Gr. du vieux perse 28, 49. But Lejeune Phon. $ 223 add. would prefer Παρσ- > Παρσ- > Περσ-, as shortening of a long vowel before sonant seems older then α > η. Perh. the word was influenced by Περσεύς, from whom the Greeks derived the name Persian.

Wikipedia EN

The Persians (Ancient Greek: Πέρσαι, Persai, Latinised as Persae) is an ancient Greek tragedy written during the Classical period of Ancient Greece by the Greek tragedian Aeschylus. It is the second and only surviving part of a now otherwise lost trilogy that won the first prize at the dramatic competitions in Athens' City Dionysia festival in 472 BC, with Pericles serving as choregos.