In the Harry Potter fandom, Grindeldore is the term that identifies the slash ship featuring Albus Dumbledore and Gellert Grindelwald. On October 19th, 2007 at Carnegie Hall in New York City, J.K. Rowling, the creator of the Harry Potter series, answered a fan's question about Dumbledore's love life by saying that she had always thought of him as gay and that he had fallen in love with Grindelwald.
The act of going behind a man (random or acquaintence) and jiggling his balls. This could be sneaky, out in the open, or an act of retaliation. No homo.
Man 1: What happened? Why do you look so surprised?
Man 2: Ho-Holy shit! Diaz just grindel swapped me!
Man 1: Oh.
The first Dark Lord within memory in the Potter-verse. Described in the book as having golden curls and being quite good-looking, and was apparently young Albus Dumbledore's best friend with whom he plotted Muggle domination. Stole the Elder Wand (see HP 7: The Deathly Hallows), the least of the Deathly Hallows. Defeated by the same Albus Dumbledore that was his best friend.
Grindelwald was defeated by Albus Dumbledore prior to the second Dark Lord, Tom Riddle.