'Smectite' definitions:

Definition of 'Smectite'

From: GCIDE

Smectite \Smec"tite\, n. [G. smectit, fr. Gr. ????? a kind of fuller's earth, fr. ????? to wipe off.] (Min.) A hydrous silicate of alumina, of a greenish color, which, in certain states of humidity, appears transparent and almost gelatinous. [1913 Webster]