Definify.com
Webster 1913 Edition
Niello
Ni-el′lo
,Noun.
1.
A metallic alloy of a deep black color.
2.
The art, process, or method of decorating metal with incised designs filled with the black alloy.
3.
A piece of metal, or any other object, so decorated.
4.
An impression on paper taken from an ancient incised decoration or metal plate.