σμηκτρίς
From LSJ
Περὶ τοῦ ἐπέκεινα τοῦ νοῦ κατὰ μὲν νόησιν πολλὰ λέγεται, θεωρεῖται δὲ ἀνοησίᾳ κρείττονι νοήσεως → On the subject of that which is beyond intellect, many statements are made on the basis of intellection, but it may be immediately cognised only by means of a non-intellection superior to intellection
English (LSJ)
ίδος, ἡ, γῆ a kind of fuller's earth, Eup.380, Nicoch.4, Cephisod.6, Hp.Mul.2.189, Fist.3.
German (Pape)
[Seite 910] ἡ, γῆ, eine Walkerde, Zeug damit zu reinigen, Poll. 7, 40, auch σμηκτίς. Vgl. Lob. Phryn. 253.
Dutch (Woordenboekgrieks.nl)
σμηκτρίς -ίδος [σμήχω] reinigend.