NEW YORK - With author J.K. Rowling's revelation that master wizard Albus Dumbledore is gay, some passages about the Hogwarts headmaster and rival wizard Gellert Grindelwald have taken on a new and clearer meaning.

The British author stunned her fans at Carnegie Hall on Friday night when she answered one young reader's question about Dumbledore by saying that he was gay and had been in love with Grindelwald, whom he had defeated years ago in a bitter fight. '"You cannot imagine how his ideas caught me, Harry, inflamed me,''' Dumbledore says in "Harry Potter and the Deathly Hallows,'' the seventh and final book in Rowling's record-breaking fantasy series.

The news brought gasps, then applause at Carnegie Hall, the last stop on Rowling's brief U.S. tour, and set off thousands of e-mails on Potter fan websites around the world. Some were dismayed, others indifferent, but most were supportive.

"Jo Rowling calling any Harry Potter character gay would make wonderful strides in tolerance toward homosexuality,'' Melissa Anelli, webmaster of the fan site , told The Associated Press. "By dubbing someone so respected, so talented and so kind, as someone who just happens to be also homosexual, she's reinforcing the idea that a person's gayness is not something of which they should be ashamed.''

"'DUMBLEDORE IS GAY' is quite a headline to stumble upon on a Friday evening, and it's certainly not what I expected,'' added Potter fan Patrick Ross, of Rutherford, N.J. "(But) a gay character in the most popular series in the world is a big step for Jo Rowling and for gay rights.''

Gellert Grindelwald was a dark wizard of great power, who terrorized people much in the same way Harry's nemesis, Lord Voldemort, was to do a generation later. Readers hear of him in the first book, "Harry Potter and the Sorcerer's Stone,'' in a reference to how Dumbledore defeated him. In "Deathly Hallows,'' readers learn they once had been best friends.

"Neither Dumbledore nor Grindelwald ever seems to have referred to this brief boyhood friendship in later life,''' Rowling writes. "However, there can be no doubt that Dumbledore delayed, for some five years of turmoil, fatalities, and disappearances, his attack upon Gellert Grindelwald. Was it lingering affection for the man or fear of exposure as his once best friend that caused Dumbledore to hesitate?''

As a young man, Dumbledore, brilliant and powerful, had been forced to return home to look after his mentally ill younger sister and younger brother. It was a task he admits to Harry that he resented, because it derailed the bright future he had been looking forward to.

Then Grindelwald, described by Rowling as "golden-haired, merry-faced,'' arrived after having been expelled from his own school. Grindelwald's aunt, Bathilda Bagshot, says of their meeting: "The boys took to each other at once.'' In a letter to Grindelwald, Dumbledore discusses their plans for gaining wizard dominance: "'(I)f you had not been expelled we would never have met.'''

Potter readers had speculated about Dumbledore, noting that he has no close relationship with women and a mysterious, troubled past.

"Falling in love can blind us to an extent,'' Rowling said Friday of Dumbledore's feelings about Grindelwald, adding that Dumbledore was "horribly, terribly let down.''

Dumbledore's love, she observed, was his "great tragedy.''