Crossword clue: a vitreous compound, used by potters in glazing, consisting of lime, silica, borax, lead, and soda.
1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).
Possible answers
The worn side of the bank of a river. See 4th Fret, n., 4.