Definition of "niello" [ni•el•lo]

• Any of several black metallic alloys of sulfur with copper, silver, or lead, used to fill an incised design on the surface of another metal. (noun)
• A surface or object decorated with one of these alloys. (noun)
• The art or process of ornamenting metal surfaces with one of these alloys. (noun)
• To decorate or inlay with niello. (verb-transitive)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Italians still call 'niello' work, or the enamelling of designs upon precious metals."
• "The Fuller Brooch is a large disc made of hammered sheet silver inlaid with black niello and with a diameter of 11.4 cm."
• "Cast and engraved bronze, partly inlaid with niello, 44.3 cm."