πτερνίς
From LSJ
καὶ νῦν περὶ ἀρετῆς ὃ ἔστιν ἐγὼ μὲν οὐκ οἶδα, σὺ μέντοι ἴσως πρότερον μὲν ᾔδησθα πρὶν ἐμοῦ ἅψασθαι, νῦν μέντοι ὅμοιος εἶ οὐκ εἰδότι → so now I do not know what virtue is; perhaps you knew before you contacted me, but now you are certainly like one who does not know
English (LSJ)
ίδος, ἡ,
A bottom of a dish, Alex.329, Ael.Dion.Fr.289.