(n) A double uncle is man who is someone's mother's brother and also that person's father's brother. In other words, a double uncle is an uncle on both sides of the family. For a double uncle to exist, a child must be a product of incest between two siblings, and the parents must share a brother.
Tyrion Lannister from A Song of Ice and Fire / Game of Thrones is probably the most well known double uncle. His double nephews don't appreciate him like a double uncle should be appreciated.
Person A: Dude, Tyrion is freaking awesome. He's probably my favourite character at the moment.
Person B: Yeah, it's a shame he's that Joffrey faggot's double uncle.
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Person A: My double uncle said he'd get us all ice creams!
Person B: Double uncles are the greatest!
Double Uncle: Now get back in my van, kids. And don't scream.
Person A: Dude, Tyrion is freaking awesome. He's probably my favourite character at the moment.
Person B: Yeah, it's a shame he's that Joffrey faggot's double uncle.
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Person A: My double uncle said he'd get us all ice creams!
Person B: Double uncles are the greatest!
Double Uncle: Now get back in my van, kids. And don't scream.
by Faguette February 21, 2014
Son of a paternal grandmother with maternal grandfather, in other words, maternal half-brother of one's father and paternal half-brother of one's mother at the same time or also is the son of a maternal grandmother with paternal grandfather, in other words, paternal half-brother of one's father and maternal half-brother of one's mother at the same time.
My double-half-uncle is a good person.
by Hgcloziw November 23, 2019