Trademark term used to denote a situation when a famous mark is used by another which diminishes the quality or reputation of the mark. Even though there may be no likelihood of customer confusion as a result of the use by the party causing the damages, there still is a cause of action for trademark infringement. A famous example was the use of the trademarked word Candyland a children’s game was used for a website selling pornography. This obviously diluted and tarnished the reputation of the children’s game by the same name. Confusion in the marketplace was likely not at issue.
DILUTION
TheLaw.com Law Dictionary & Black's Law Dictionary 2nd Ed.