Grundel is another word for chad: the region between the balls and the arse-hole; can be an erogenous zone for some.
Girl: I was fingering that part between his balls and his arse and there was shit there.
Everyone listening remained silent but later laughed among themselves:
'Eww! He had a shitty chad.'
When you measure your dick, you don't start at the arse-hole and include the chad; you risk getting shit on your measuring tape.
Q: What on earth is a grundel?
A: You know, the chad, the part between balls and arse.
In the Harry Potter fandom, Grindeldore is the term that identifies the slashship 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.
My gaydar went off all over Grindeldore when I firstread the Deathly Hallows, didn't yours?
Based on the character from the Anglo-Saxon tale Beowulf. Refers to someone who stays locked up in their room, with the curtains closed, and only wants peace and quiet. If their wishes are not met they will huff and puff and possibly even massacre a large group of people.
Hannah: Hey, is Zena coming out tonight?
Jill: No, she's grendeling as usual.