Discussion of Greek nouns/adjectives in -ειον/-ειον-derived forms, their accentuation (proparoxytone vs. non-proparoxytone), and example words and meanings.
ἢ κώνειον, γένειον, δάνειον, κράνειον, κάνειον ὃ καὶ κάνεον, Φάνειον, Πάνειον, κτένειον, ὃ φοροῦσιν αἱ γυναῖκες ἐπὶ τοῦ ἀναδήματος, κύνειον. τὸ δὲ κοινεῖον προπερισπᾶται οὐκ εἰς ἓν φωνῆεν λῆγον καὶ λυχνεῖον καὶ πορνεῖον, οὐ μόνον ἔχοντα τὸ 'ν'. * Τὰ διὰ τοῦ 'ειον' μονογενῆ τρισύλλαβα ἀπὸ ἑνὸς συμφώνου ἀρχόμενα ἔχοντα τὸ 'η' ἢ τὸ 'ω', μὴ ἔχοντα τὸ 'μ' πρὸ τῆς 'ει' διφθόγγου, προπαροξύνεται, κώρειον, ζήτρειον καὶ ζώτειον, ὁ μύλος ὅπου αἱ ζειαὶ ἐκόπτοντο ἢ τόπου ὄνομα ὅπου οἱ δοῦλοι ἐκολάζοντο, γήτειον, χήλειον ὃ καὶ χέλειον, γήρειον, βήχειον ἡ βοτάνη, κήτειον ἡ βοτάνη τῇ ἀνθέρικι παραπλήσιον εἰς ἔμετον ἐπιτήδειος, μεθ´ ὧν καὶ βρένθειον εἶδος πολυτελοῦς μύρου. Τὰ διὰ τοῦ 'ειον' μονογενῆ τρισύλλαβα χωρὶς τῶν εἰρημένων προπερισπᾶται, πορθμεῖον, στοιχεῖον, ἀγγεῖον, γραφεῖον, ᾠδεῖον, σημεῖον, μνημεῖον, πρωτεῖον, σφηκεῖον, ἠχεῖον, πορνεῖον, λυχνεῖον, ἀρχεῖον, φυλλεῖον τῶν λαχάνων τὸ ἕωλον καὶ φαῦλον, χυτρεῖον, χυρρεῖον τὸ ξύλινον δεσμωτήριον. τοπεῖον τὸ σχοινίον τῆς νεώς. σκαφεῖον τὸ γεωργικὸν ἐργαλεῖον, κουρεῖον τὸ κοινῶς λεγόμενον. τὸ δὲ ἰδίως παρ´ Ἀθηναίοις προπαροξύνεται· οὕτω γὰρ καλεῖται ἐν Ἀττικῇ τὸ ἱερεῖον θυόμενον, ἡνίκα ἐγράφοντο οἱ κοῦροι εἰς τοὺς φράτορας. χαλκεῖον τόπος καὶ ἑορτή. τοῦτο γὰρ ἡ πλείων χρῆσις προπερισπᾷ. πρεσβεῖον, λοφεῖον ἡ θήκη τῆς περικεφαλαίας. μουσεῖον, βραβεῖον, φορεῖον, πορεῖον ἀντὶ τοῦ ὀχήματος. ποδεῖον εἴλημα τῶν ποδῶν. πομπεῖον ὁ τόπος. ὀχεῖον ἡ ἄγκυρα. τὸ δὲ παρειόν «ὦχρος δέ μιν εἷλε παρειά» (Γ 35) ὀξύνεται. τὰ γὰρ ἀπὸ τῶν τοιούτων θηλυκῶν μεταποιούμενα εἰς οὐδέτερον γένος τοῦ αὐτοῦ σημαινομένου μένοντος τὸν αὐτὸν φυλάσσει τόνον, πλευραί πλευρά, πυραί πυρά. οὐκ ἀντίκειται τὸ νευραί καὶ νεῦρα. διάφορον
Either κώνειον, γένειον, δάνειον, κράνειον, κάνειον (also κάνεον), Φάνειον, Πάνειον, κτένειον, which women wear as a headband, κύνειον. But κοινεῖον is circumflexed on the penult, not because it ends in a single vowel, nor (is) λυχνεῖον and πορνεῖον (so circumflexed), not only those that have the ‘ν’.
The trisyllabic, single-gender words in -ειον, beginning with a single consonant and having η or ω, not having μ before the diphthong ει, are accented on the antepenult: κώρειον, ζήτρειον and ζώτειον (the mill where the ζειαί were crushed, or a place-name where slaves were punished), γήτειον, χήλειον (also χέλειον), γήρειον, βήχειον (the plant), κήτειον (the plant similar to ἀνθέρικη, suitable for inducing vomiting), along with which also βρένθειον, a kind of costly perfume.
The trisyllabic, single-gender words in -ειον, apart from those mentioned, are circumflexed on the penult: πορθμεῖον, στοιχεῖον, ἀγγεῖον, γραφεῖον, ᾠδεῖον, σημεῖον, μνημεῖον, πρωτεῖον, σφηκεῖον, ἠχεῖον, πορνεῖον, λυχνεῖον, ἀρχεῖον, φυλλεῖον (the stale and worthless part of vegetables), χυτρεῖον, χυρρεῖον (the wooden prison). τοπεῖον, the ship’s rope. σκαφεῖον, the farming implement; κουρεῖον, the word in common use. But the one used specifically among the Athenians is accented on the antepenult; for thus in Attic is called the sacrificial victim being offered, when the youths were enrolled among the phratries. χαλκεῖον, a place and a festival; for the more common usage circumflexes this on the penult. πρεσβεῖον, λοφεῖον (the case for the helmet), μουσεῖον, βραβεῖον, φορεῖον, πορεῖον in place of ὄχημα. ποδεῖον, a covering for the feet. πομπεῖον, the place. ὀχεῖον, the anchor. But the form παρειόν in «ὦχρος δέ μιν εἷλε παρειά» (Γ 35) is accented with an acute. For neuters formed from such feminines, with the same meaning remaining, keep the same accent: πλευραί, πλευρά; πυραί, πυρά. The pair νευραί and νεῦρα is not an objection. Different…