Definition of tarnish
- to damage or ruin the good quality of something, such as a person's reputation, image, etc.
- to become or cause metal to become dull and not shiny
Usage examples of tarnish
The false accusation could tarnish her reputation for years.
Moist air can tarnish silver if it is not stored carefully.
He polished the tray before the dark spots could tarnish the metal.