NIELLO

I. noun (plural nielli or ~s) Etymology: Italian, from Medieval Latin nigellum, from neuter of Latin nigellus blackish, diminutive of niger black Date: 1816 any of several black enamel-like alloys usually of sulfur with silver, copper, and lead, the art or process of decorating metal with incised designs filled with ~, a piece of metal or an object decorated with ~, II. transitive verb Date: 1866 to inlay or ornament with ~