ἐν πέτροισι πέτρον ἐκτρίβων → by grinding stone against stones
subs.
Use Ar. and P. κάθαρμα, τό, περίτριμμα, τό. Mob: P. and V. ὄχλος, ὁ, P. συρφετός, ὁ (Plat.).
