Grammatical discussion of accentuation and gender patterns for disyllabic nouns and ethnics ending in -δος (e.g. ὁδός, σποδός, Μῆδος, Ῥόδος, Λίνδος, Σάρδος), noting oxytone/paroxytone behavior and exceptions.
τὸ μέντοι ὁδός καὶ σποδός ὀξύνεται ὡς θηλυκὰ προσηγορικὰ τῷ 'ο' παραλήγοντα. Τὰ εἰς 'δος' δισύλλαβα 'ο' ἢ 'ου' ἢ 'οι' διφθόγγῳ ἢ 'η' παραληγόμενα, εἰ μὴ σύνθετα ὑπάρχοι ἢ ἐθνικά, ὀξύνεται, ὁδός, σποδός, οὐδός· τὸ δὲ φροῦδος ἀπὸ τοῦ πρόοδος σύνθετον καὶ τὸ Μῆδος ἐθνικόν. σεσημείωται τὸ σκοῖδος παρὰ Μακεδόσιν ὁ οἰκονόμος καὶ τὸ χλῆδος προπερισπώμενα καὶ τὸ Ῥόδος παροξυνόμενον. Τὰ εἰς 'δος' ἀρσενικὰ φύσει μακρᾷ παραληγόμενα βαρύνεται Μῆδος υἱὸς Μηδείας καὶ τὸ ἐθνικὸν ὁμοφώνως τῷ πρωτοτύπῳ, νῖδος (?) ζεῦδος (?). Βλαῦδος πόλις Φρυγίας. τὸ μέντοι καυδός θηλυκὸν ὥσπερ καὶ τὸ μαυδός. σεσημείωται τὸ Μαιδός ἔθνος Θρᾴκης πλησίον Μακεδονίας καὶ Ἠδός ἔθνος Σκυθικόν. Ἑκαταῖος Εὐρώπῃ καὶ Λυδός. Τὰ εἰς 'δος' δισύλλαβα ἔχοντα πρὸ τοῦ 'δ' σύμφωνον κατ´ ἐπιπλοκὴν βαρύνεται, Σόγδος ὁ οἰκήτωρ Σογδιανῆς. λέγεται καὶ Σόγδιος. ῥάβδος. ἄσδος στήλη λιθίνη, λύγδος, Ῥύβδος φρούριον Σικελίας. Τὰ εἰς 'δος' δισύλλαβα ἔχοντα πρὸ τοῦ 'δ' σύμφωνον κατὰ διάστασιν βαρύνεται, εἰ μὴ ἐπιθετικὰ εἴη, Λίνδος πόλις ἐν Ῥόδῳ κτίσμα Λίνδου τοῦ Κερκάφου, τοῦ Ἡλίου καὶ Κυδίππης, τῆς Ὀχίμου θυγατρός. ἔστι καὶ Σικελίας πόλις Λίνδος. Σίνδος ἔθνος ἀπὸ μεσημβρίας τῆς Μαιώτιδος λίμνης. τινὲς δὲ ὀξυτονοῦσιν, οὐκ εὖ, Πίνδος, νάρδος, μάρδος αὐλοῦ εἶδος καὶ ἔθνος Ὑρκάνιον. Ἀπολλόδωρος περὶ γῆς δευτέρῳ. πάρδος. Σάρδος πόλις Ἰλλυρίας, Βάλδος πόλις Φοινίκης, Χάλδος ἔθνος τῆς Ἀρμενίας. οὕτως γὰρ λέγεσθαι ἐπεκράτησεν ἡ συνήθεια δισυλλάβως, οὐ Χαλδαίους. Μύνδος πόλις Καρίας. Ἑκαταῖος Ἀσίᾳ. Γόρδος ἔθνος, ὃ καὶ Γορδυαῖος καὶ Γόρδοχος καλεῖται. σεσημείωται τὸ Ἰνδός ποταμὸς καὶ ἐθνικὸν καὶ Ὀρδός ἔθνος Μακεδονίας. λέγονται καὶ Ὀρδαῖοι, ὡς Νίκανδρος. τὸ δὲ λορδός ἐπίθετον καὶ ὁ μυνδός ὁ ἄφωνος, ἀφ´ οὗ «μυνδότεροι νεπόδων» παρὰ Καλλιμάχῳ.
However, ὁδός and σποδός are accented with an acute, as feminine appellatives with penult in -ο. Disyllables in -δος with penult in ο or ου or the diphthong οι or in η, if they are not compounds or ethnics, are accented with an acute: ὁδός, σποδός, οὐδός; but φροῦδος is a compound from πρόοδος, and Μῆδος is an ethnic. Noted are σκοῖδος among the Macedonians, meaning “the steward,” and χλῆδος, with circumflex on the antepenult, and Ῥόδος, with acute on the penult. Masculines in -δος with penult naturally long are accented with a grave: Μῆδος, son of Medeia, and the ethnic likewise, with the same accent as the primitive; νῖδος (?), ζεῦδος (?). Βλαῦδος, a city of Phrygia. However, καυδός is feminine, as also μαυδός. Noted are Μαιδός, a Thracian people near Macedonia, and Ἠδός, a Scythian people. Hecataeus in the Europa, and Λυδός. Disyllables in -δος having before δ a consonant in combination are accented with a grave: Σόγδος, the inhabitant of Sogdiana; it is also said Σόγδιος. ῥάβδος. ἄσδος, a stone stele; λύγδος; Ῥύβδος, a fortress of Sicily. Disyllables in -δος having before δ a consonant in separation are accented with a grave, unless they are adjectival: Λίνδος, a city in Rhodes, a foundation of Lindus son of Cercaphus, of Helios and Cydippe, daughter of Ochimus; there is also in Sicily a city Lindos. Σίνδος, a people south of the Maeotic lake. Some, not rightly, accent with an acute Πίνδος, νάρδος, μάρδος, a kind of pipe and a Hyrcanian people; Apollodorus in the second book On the Earth. πάρδος. Σάρδος, a city of Illyria; Βάλδος, a city of Phoenicia; Χάλδος, a people of Armenia; for usage has prevailed to say it thus as a disyllable, not Χαλδαίους. Μύνδος, a city of Caria; Hecataeus in the Asia. Γόρδος, a people, who are also called Γορδυαῖος and Γόρδοχος. Noted are Ἰνδός, a river and an ethnic, and Ὀρδός, a people of Macedonia; they are also called Ὀρδαῖοι, as Nicander has it. But λορδός is an adjective, and μυνδός means “speechless,” from which comes in Callimachus “μυνδότεροι νεπόδων.”