List of geographic place-names (toponyms) with the suffix -ιον and related ethonyms, brief citations (e.g., Pausanias, Hellanicus), notes on variants and gender, orthographic and phonological remarks about diphthongs ('ι' vs 'ει') and accentuation rules for neuter nouns in -ιον, plus a few related lexical items (e.g., ἐρίπιον, προνώπιον).
διὰ οὖν τὰς εἰκόνας ἐκεῖ διαγραφῆναι Ἰκόνιον κληθῆναι. καὶ ἔδει διὰ διφθόγγου. Πελεθρόνιον ὄρος Θετταλίας. Παραιτόνιον πόλις πλησίον Ἀλεξανδρείας, ἣν Ἀμμωνίαν καλοῦσι. Λινδόνιον πόλις τῆς Βρεττανίας. Φλυγόνιον πόλις Φωκίδος. λέγεται καὶ θηλυκῶς Φλυγονία. Ἀργύννιον. Ἀριστοφάνης δὲ Ἀργύννειον διὰ διφθόγγου. Βιθύνιον πόλις Βιθυνίας. Παυσανίας ὀγδόῳ ( 9, 7). Ἑρκύνιον ὄρος Ἰταλίας, ἀφ´ οὗ Ἑρκυνίς ἡ χώρα καὶ Ἑρκύνιος τὸ κτητικόν. Ἀλέξανδρος Εὐρώπῃ. Ἀρδύνιον πόλις ἐν Θήβης πεδίῳ, ὡς Ξάνθος ἐν Λυδιακῶν δευτέρῳ. παιώνιον, κωδώνιον, χελώνιον, ὀψώνιον, χιτώνιον, τριβώνιον, πωγώνιον, Πλατώνιον, Ἱππώνιον πόλις Βρεττίων, ἀπὸ ἥρωος. Ἀσκαλώνιον. καὶ οὕτως λέγεται ἡ πόλις Ἀσκάλων. Πανιώνιον τέμενος καὶ πόλις ἐν τῇ παραλίᾳ τῶν Ἐφεσίων καὶ Σαμίων. Μεταγώνιον πόλις Λιβύης. Ἑκαταῖος Ἀσίᾳ. θηλυκῶς δὲ ταύτην φασί. Θεμισώνιον χωρίον Φρυγίας. Ἀρτεμίδωρος. Λαμπώνιον πόλις Τρῳάδος. Ἑλλάνικος, Ἑκαταῖος δὲ Ἀσίᾳ Λαμπώνειαν αὐτήν φησι. Θηγώνιον πόλις Θεσσαλίας. Ἑλλάνικος πρώτῃ Δευκαλιωνείας. Κυτώνιον πόλις μεταξὺ Μυσίας καὶ Λυδίας. Θεόπομπος Ἑλληνικῶν ὀγδόῳ. Πολεμώνιον ἐν Πόντῳ λιμὴν καὶ πόλις. Ποπλώνιον πόλις Τυρρηνῶν. Σκιρτώνιον πόλις Ἀρκαδίας, ὡς Παυσανίας ὀγδόῳ ( 27, 4). Ταρχώνιον πόλις Τυρρηνίας, ἀπὸ Τηλέφου παιδὸς Τάρχωνος. Τιθρώνιον Φωκικὴ πόλις. Τιμώνιον πόλις Παφλαγονίας. Τριχώνιον πόλις Αἰτωλίας. Γερούνιον πόλις Ἰταλίας. Ἐλύμνιον νῆσος Εὐβοίας πόλιν ἔχουσα. λέγεται καὶ Ἐλυμνία. * Τὰ εἰς 'ιον' 'ξ' ἢ 'π' παραληγόμενα οὐδέτερα ὑπὲρ τρεῖς συλλαβὰς προπαροξύνεται, Ἀμφάξιον πόλις. δύο μέρη λόγου. Ὑπερδέξιον χωρίον Λέσβου, ἐν ᾧ Ζεὺς Ὑπερδέξιος καὶ Ὑπερδεξία Ἀθηνᾶ. ἐρείπιον. καὶ λέγει ὁ Δίδυμος, ὅτι τὸ ἐρίπω καὶ ἐρίπια διὰ τοῦ 'ι' ὤφειλε γράφεσθαι, ἐπειδὴ παρὰ τὸ ἐρίπνη ἐστίν, ὅπερ σημαίνει τὴν μεγάλως περιπνεομένην. τὸ δὲ ἐρίπνη διὰ τοῦ 'ι' παρὰ τὴν ἐρί ἐπίτασιν. ὁ δὲ Φιλόξενος λέγει, ὅτι ἐρίπω διὰ τοῦ 'ι' ὤφειλεν, ὡς καὶ Δίδυμος. εἰπὼν δὲ «ὤφειλεν» ἐδήλωσεν οὐ διὰ τοῦ 'ι' γράφεσθαι, ἀλλὰ διὰ τῆς 'ει' διφθόγγου. οὕτως γὰρ ἔχει ἡ παράδοσις. ἔστι δὲ καὶ ἀπὸ τοῦ ἔρα ἡ γῆ ἐρέπτω καὶ πλεονασμῷ τοῦ 'ι' καὶ ἀποβολῇ τοῦ 'τ' ἐρείπω καὶ ἐρείπια. ἐνώπιον τὸ ἔνδον τῶν θυρῶν, προνώπιον τὸ ἔμπροσθεν τῶν θυρῶν ἔνθα αἱ εἰκόνες τίθενται, ἀνθρώπιον, παρώπιον τὸ
Therefore, because the images were drawn there, it was called Ἰκόνιον. And it ought to be with a diphthong. Πελεθρόνιον, a mountain of Thessaly. Παραιτόνιον, a city near Alexandria, which they call Ἀμμωνία. Λινδόνιον, a city of Britain. Φλυγόνιον, a city of Phocis; it is also said in the feminine, Φλυγονία. Ἀργύννιον; but Aristophanes has Ἀργύννειον with a diphthong. Βιθύνιον, a city of Bithynia; Pausanias in the eighth book (9, 7). Ἑρκύνιον, a mountain of Italy, from which come Ἑρκυνίς, the region, and Ἑρκύνιος, the possessive adjective; Alexander in his work On Europe. Ἀρδύνιον, a city in the plain of Thebes, as Xanthus says in the second book of his Lydian history. παιώνιον, κωδώνιον, χελώνιον, ὀψώνιον, χιτώνιον, τριβώνιον, πωγώνιον, Πλατώνιον. Ἱππώνιον, a city of the Brettii, from a hero. Ἀσκαλώνιον; and thus the city Ἀσκάλων is spoken of. Πανιώνιον, a precinct and a city on the coast of the Ephesians and Samians. Μεταγώνιον, a city of Libya; Hecataeus in his Asia. They also say this in the feminine. Θεμισώνιον, a place in Phrygia; Artemidorus. Λαμπώνιον, a city of the Troad; Hellanicus, but Hecataeus in his Asia says that it is Λαμπώνειαν. Θηγώνιον, a city of Thessaly; Hellanicus in the first book of his Deucalioneia. Κυτώνιον, a city between Mysia and Lydia; Theopompus in the eighth book of his Hellenica. Πολεμώνιον in Pontus, a harbor and a city. Ποπλώνιον, a city of the Tyrrhenians. Σκιρτώνιον, a city of Arcadia, as Pausanias in the eighth book (27, 4). Ταρχώνιον, a city of Tyrrhenia, from Τάρχων, son of Telephus. Τιθρώνιον, a Phocian city. Τιμώνιον, a city of Paphlagonia. Τριχώνιον, a city of Aetolia. Γερούνιον, a city of Italy. Ἐλύμνιον, an island of Euboea having a city; it is also called Ἐλυμνία.
* Neuters in -ιον whose penult ends in ξ or π, when they are more than three syllables, are accented on the antepenult: Ἀμφάξιον, a city—two parts of speech. Ὑπερδέξιον, a place of Lesbos, in which are Zeus Ὑπερδέξιος and Ὑπερδεξία Athena. ἐρείπιον. And Didymus says that ἐρίπω and ἐρίπια ought to be written with ι, since they are from ἐρίπνη, which means “greatly wind-swept.” And ἐρίπνη is written with ι from the intensive prefix ἐρί-. But Philoxenus says that ἐρίπω ought to be with ι, as Didymus too. But by saying “ought” he made clear that it is not written with ι, but with the diphthong ει; for thus the tradition has it. There is also, from ἔρα “earth,” ἐρέπτω, and by addition of ι and loss of τ, ἐρείπω and ἐρείπια. ἐνώπιον is “the inside of the doors,” προνώπιον “the space in front of the doors where the images are set,” ἀνθρώπιον, παρώπιον, the…