■ verb
1》 lose or cause to lose lustre, especially as a result of exposure to air or moisture.
2》 make less valuable or respected: they make up negative stories to ~ my image.
■ noun loss of brightness.
↘a film or stain formed on an exposed surface of a mineral or metal.
Derivatives
~able adjective
Origin
ME: from Fr. terniss- , lengthened stem of ternir , from terne 'dark, dull'.