Βυζάντιον
From LSJ
καὶ κεραμεὺς κεραμεῖ κοτέει καὶ τέκτονι τέκτων, καὶ πτωχὸς πτωχῷ φθονέει καὶ ἀοιδὸς ἀοιδῷ → and potter is ill-disposed to potter, and carpenter to carpenter, and the beggar is envious of the beggar, the singer of the singer
French (Bailly abrégé)
ου (τό) :
Byzance (Constantinople) ville de Thrace, sur le Bosphore.
Russian (Dvoretsky)
Βυζάντιον: τό Византия (город на фракийском берегу Боспора, ныне Стамбул) Her., Arst.