From the Suda
Idiôtai: Private individuals, used in place of citizens [politai]. This is how Thucydides uses it. But in the Frogs, Aristophanes calls idiots the people who are your own—“regarding strangers and idiots. It is derived from the word idios. And so idiôtês is what they call someone who is related to you by clan; but it is also an unlearned person. And in his Wealth, Aristophanes also uses idiôtikon as that which belongs to a person privately or idion as one’s own.
᾿Ιδιῶται: ἀντὶ τοῦ πολῖται. οὕτως Θουκυδίδης. ᾿Αριστοφάνης δὲ ἐν Βατράχοις ἰδιώτας τοὺς ἰδίους λέγει· περὶ τοὺς ξένους καὶ τοὺς ἰδιώτας· κατὰ παραγωγὴν ἴδιος, ἰδιώτης. ἰδιώτης δὲ λέγεται, ὁ πρὸς γένος ἴδιος, καὶ ὁ ἀμαθής. καὶ ἐν Πλούτῳ ἴδιον τὸ ἰδιωτικόν φησιν.
ἰδιάζω: “to live as a private person”
ἰδιόβιος: “living by or for oneself”
ἰδιόγλωσσος: “of distinct, peculiar tongue”
ἰδιογνώμων: “private opinion”
ἰδιοθανέω: “to die in a peculiar way”
ἰδιολογία: “private conversation”
ἰδιοξενία: “private friendship”
ἰδιοπάθεια: “feeling for oneself alone”
Also from the Suda
Idiôtês: someone who is illiterate. Damaskios writes about Isidore: “of all the idiots and all the philosophers of his time he was equally tight-lipped generally and he hid his thoughts. But he poured his mind out into the shared increase of virtue and the limit of vice.”
᾿Ιδιώτης: ὁ ἀγράμματος. Δαμάσκιος περὶ ᾿Ισιδώρου φησί· πάντων τῶν καθ’ αὑτὸν ἰδιωτῶν ὁμοίως καὶ φιλοσόφων ἐχέμυθος ἐς τὰ μάλιστα καὶ κρυψίνους ἦν, ἀλλ’ εἴς γε συναύξησιν τῆς ἀρετῆς καὶ τῆς κακίας μείωσιν ὅλην ἐξεκέχυτο τὴν ψυχήν.