ἐν πέτροισι πέτρον ἐκτρίβων → by grinding stone against stones
subs.
P. and V. θριγκός, ὁ (Plat.), V. γεῖσα, τά. Met., P. κολοφών, ὁ, P. and V. θριγκός, ὁ (Plat.).
Put coping-stone to: Met., P. κολοφῶνα, ἐπιτιθέναι (dat.) (Plat.), V. θριγκοῦν (acc.); see crown.
