α922Ἀκόνη
whetstone
[Meaning a particular kind of] stone. And [there is] a proverb: "you are feeding a whetstone", in reference to those consuming food but deriving no benefit to the body.
Ἀκόνη· λίθος. καὶ παροιμία· Ἀκόνην σιτίζεις, ἐπὶ τῶν τροφῇ μὲν χρωμένων, μηδὲν δὲ εἰς τὸ σῶμα ἐπιδιδόντων.