ψυχῶν σοφῶν φροντιστήριον → thought-shop of wise souls
P. ἄμμος, ἡ (Plato), Ar. and V. ψάμαθος, ἡ (Sophocles, Ajax 1064).
shingle: P. κάχληξ, ὁ.
dust: P. and V. κόνις, ἡ.