Discussion of accentuation patterns for Greek nouns ending in -ρον, with examples (household items and place-names) and rules about barytone (recessive) and proparoxytone forms.
Τὰ εἰς 'ρον' ὑπὲρ δύο συλλαβὰς τῷ 'υ' παραληγόμενα βαρύνεται, ἄχυρον, πίτυρον, ἐνέχυρον, πρόθυρον, βούτυρον, λέπυρον, ἄστυρον. ἔστι καὶ Ἄστυρον πόλις Μυσίας πρὸς τῇ Τρῳάδι, ἣ καὶ πληθυντικῶς λέγεται· ἔστι καὶ κώμη πλησίον τοῦ Ἀδραμυττίου, ὡς Στράβων. ἔστι καὶ πόλις Φοινίκης κατ´ Ἄραδον, ἐν ᾗ ἐτιμᾶτο ἡ Ἀθηνᾶ Ἀστυρίς. ἔστι καὶ Βοιωτίας πρὸς ταῖς Ποτνίαις, ὡς Χάραξ ἐν δευτέρᾳ. ἔστι καὶ χωρίον Ἰταλίας. Κίχυρον, Πάλμυρον, Σίμυρα· οὕτως οὐδετέρως Ἔφορος Σίμυρον πόλιν Σύρων φησί. Ἀτάβυρον ὄρος Ῥόδου Ῥιανὸς ἕκτῳ Μεσσηνιακῶν. Ἄγγυρον ὄνομα ὄρους. Τίβυρα. οὕτως Ἀρτεμίδωρος τετάρτῳ γεωγραφουμένων Τίβυριν πόλιν Ἰταλίας καλεῖ. Τὰ εἰς 'ρον' κατ´ ἐπιπλοκὴν συμφώνου δισύλλαβα βαρύνεται ῥεῖθρον, κλεῖθρον, φίλτρον, κέντρον, ἄρθρον, πλῆκτρον, νίτρον, ἄντρον τὸ σπήλαιον. βλῆτρον. Βάκτρα πόλις. Στράβων ιαʹ. Σύμβρα Φρυγίας φρούριον. σεῖστρον, δένδρον, δέρτρον »δέρτρον ἔσω δύνοντες« (λ 578), φέρτρον »κείμενον ἐν φέρτρῳ« (Σ 236), καὶ ἄλλο πλῆθος τῶν τοιούτων ὀνομάτων ἀδιάπτωτον. σεσημείωται τὸ λουτρόν ὀξυνόμενον, ὅπερ καὶ τρισύλλαβον λέγεται λοετρόν »εἰς ὅ κε θερμὰ λοετρά« (Ξ 6), ἐπεὶ καὶ τὸ ῥῆμα δισσόν, λοέω καὶ λούω »ἀλλ´ ὅτε δή μιν ἐγὼ λόεον« (δ 252). * Τὰ εἰς 'ρον' οὐδέτερα μετ´ ἐπιπλοκῆς συμφώνου, ὑπὲρ δύο συλλαβὰς ὄντα, προπαροξύνεται, πέλεθρον, τέρεθρον, βέρεθρον, φέλετρον καὶ τὰ φέλετρα, θύρετρον. Ἀλάβαστρα πόλις Φρυγίας. Σύαγρα χωρίον Κιλικίας πλησίον Ἄδου καὶ Λαέρτου. Θέρμυδρα
Words ending in -ρον, of more than two syllables, with υ in the penult, are barytone: ἄχυρον, πίτυρον, ἐνέχυρον, πρόθυρον, βούτυρον, λέπυρον, ἄστυρον. There is also Ἄστυρον, a city of Mysia in the Troad, which is also spoken of in the plural; there is also a village near Adramyttium, as Strabo says. There is also a city of Phoenicia opposite Aradus, in which Athena Ἀστυρίς was honored. There is also one in Boeotia near Potniae, as Charax says in the second book. There is also a place in Italy. Κίχυρον, Πάλμυρον, Σίμυρα; thus, in the neuter, Ephorus says that Σίμυρον is a city of the Syrians. Ἀτάβυρον, a mountain of Rhodes: Rhianus in the sixth book of the Messenian poems. Ἄγγυρον, the name of a mountain. Τίβυρα. Thus Artemidorus in the fourth book of his Geography calls Τίβυριν a city of Italy. Disyllables ending in -ρον with consonant-cluster are barytone: ῥεῖθρον, κλεῖθρον, φίλτρον, κέντρον, ἄρθρον, πλῆκτρον, νίτρον, ἄντρον, “the cave.” βλῆτρον. Βάκτρα, a city: Strabo, book 11. Σύμβρα, a fortress of Phrygia. σεῖστρον, δένδρον, δέρτρον, “going down within the δέρτρον” (λ 578), φέρτρον, “lying in a φέρτρον” (Σ 236), and another multitude of such names, with unvarying accent. The word λουτρόν is noted as being oxytone, and it is also said as a trisyllable, λοετρόν: “into which there were warm λοετρά” (Ξ 6), since the verb too is double, λοέω and λούω: “but when I was bathing him” (δ 252). Neuter words ending in -ρον with consonant-cluster, being of more than two syllables, are proparoxytone: πέλεθρον, τέρεθρον, βέρεθρον, φέλετρον and τὰ φέλετρα, θύρετρον. Ἀλάβαστρα, a city of Phrygia. Σύαγρα, a place in Cilicia near Adus and Laertus. Θέρμυδρα.