The US Patent and Trademark Office has cancelled the federal registration of the Washington Redskins' name after it agreed that it is "disparaging of Native Americans".
The decision, which the American football team can appeal, is a victory for American Indians and their supporters for whom "redskins" is a racially charged word.
In a statement, the Patent Office said five Native American petitioners had "met their burden to establish that the term 'Redskins' was disparaging of Native Americans, when used in relation to professional football services."
While the team can keep using the name, it will no longer enjoy the protection from copyright infringement and counterfeiting that comes with federal registration, it said.
Dan Snyder, owner of the National Football League (NFL) franchise, has been insistent about retaining the name despite a growing national campaign spearheaded by the Oneida tribe in upstate New York.
"If the most basic sense of morality, decency and civility has not yet convinced the Washington team and the NFL to stop using this hateful slur, then hopefully today's patent ruling will," said Oneida representative Ray Halbritter.
That is because "it imperils the ability of the team's billionaire owner to keep profiting off the denigration and dehumanisation of Native Americans," said Mr Halbritter in an email.