noun / verb
tarnish
TAR-nish/ˈtɑːrnɪʃ/
Discoloration dulling a metal surface.
Dull gray-black tarnish covers the silver goblet and hides its shine.

Etymology
The French verb meant to dull brightness or luster. English applied this especially to metals losing their shine, then extended the image to tainted purity or damaged reputation: something valued loses its former brilliance.
In context
One of the most destructive behaviors is gossip. Envious people invent stories, twist facts, and spread malicious comments to tarnish your image.
More examples
- Silver tarnishes when exposed to certain compounds in the air.
- She gently removes the tarnish from the antique spoons.
- Moisture has tarnished the brass handles.
Forms
tarnish · tarnishes · tarnished · tarnishing