Tom Brady is very, very good at his job.
But, according to New Yorkers, Boston-haters and one crucial federal agency, he is decidedly not terrific.
Indeed, on Thursday, no less an adversary than the United States Patent and Trademark Office pinned a big L on Mr. Brady, the superstar quarterback of the New England Patriots, when it declined his application to trademark the term “Tom Terrific” — a moniker long associated with Tom Seaver, the beloved New York Mets right-hander who helped pitch the team to a World Series championship in 1969.
The decision was blunt in its assessment of Mr. Brady’s case for the nickname, saying it could “falsely suggest a connection” with Mr. Seaver, who the office stressed was “uniquely and unmistakably” the only person associated with the nickname.
“Tom Seaver is so well known that consumers would presume a connection,” the office wrote.
Mr. Brady has been a mainstay in Boston for two decades, and his six Super Bowl wins have left some rabid Patriots fans calling him “Tom Terrific” as well, a nickname he has said he doesn’t like. Both he and his representatives insisted that their attempt to trademark the moniker was to prevent third parties from capitalizing on the unprotected nickname, both to his and Mr. Seaver’s detriment.
“A situation arose, unfortunately, where we had to consider an immediate defensive and protective action,” said Donald H. Yee, Mr. Brady’s agent, on Friday. “There is no intention ever to impact Tom Seaver’s legacy.”
But the news of the trademark attempt had provoked the ire of Mets fans, who were happily celebrating its downfall on Friday.
“I don’t buy the ‘I was protecting Seaver’ story,” said Mike Stuto, a longtime Mets loyalist. “Seaver and his family can protect his legacy without Tom Brady’s help.”
The decision also seemed to have accomplished an even more astounding feat, uniting Yankees and Mets fans in a moment of told-you-so schadenfreude in relation to Boston, New York’s archrival in everything from sports to marathons.
“Someone at the U.S. Patent Office must be a Mets fan,” Dana Monks, a self-described lifelong Yankees fan, wrote on Twitter.
The defeat at the hands of the patent office comes even as many New York sports fans have been gleefully watching the struggles of various Boston franchises: the Boston Bruins losing the Stanley Cup, the Celtics crashing out of the second round of the N.B.A. playoffs and — of course — the world champion Red Sox, who are 15 games behind the Yankees and unlikely to make the playoffs.
At the same time, Mr. Seaver’s own Mets have been surging, causing a spike of pride in Queens and dreams of a Subway Series, an intracity championship showdown last experienced in 2000.
Of course, considering Mr. Brady’s dominance in the N.F.L., the joy was hardly confined to the tristate area. Matt Talansky, an exiled Mets fan living in Los Angeles, practically cackled at Mr. Brady’s legal fumble. Mr. Talansky recalled how Mr. Brady was suspended following a 2015 championship game for his role in a scandal involving deflating footballs in a playoff game.
“Has anyone ever even called him ‘Tom Terrific’?” Mr. Talansky said. “Was ‘Vainglorious Cheater’ already trademarked?”
It was also being shared by fans of such long suffering franchises as the Cleveland Browns, a team that has never appeared in the Super Bowl. “Even the government knows that Tom Seaver is the true ‘Tom Terrific,’” wrote one such Ohioan, in all capital letters, on Twitter.
Mr. Brady’s actions were also seen as insensitive by some considering Mr. Seaver’s declining health; in March, his family announced that the Hall of Famer, now 74, was suffering from dementia and was retiring from public life.
Mr. Brady himself had expressed regret about pursuing the trademark, telling reporters in June that “I wanted to make sure no one used it because some people wanted to use it,” Brady said, calling it a “good lesson learned.”
“I’ll try to do things a little different in the future,” he said.
Still, for New York sport fans, who have often been on the bad end of Mr. Brady’s good days, his loss this week seemed even sweeter.
“As a Mets/Jets fan,” said Cory Dann, 42, a die-hard from Brooklyn, “it’s nice to finally beat Tom Brady at something.”