n. In ceramics, the process of testing the surface of gilding, after it has been fired, with fine sand and water, to try whether the firing has been insufficient (in which case the gold will not adhere) or excessive (in which case the gold will not be brilliant).n. The process of burying oysters in sand, mud, etc.; also, accumulation of foreign matter on their shells, or this matter itself.n. The act of mixing with sand.