Top definition
The name in the Harry Potter wizarding world for Lord Voldemort. He has also been called "He Who Must Not Be Named", "Lord Thingy", and other appellations of the sort.
Ron: "Hey, Hermione, I heard that You-Know-Who is trying to find Harry. D'you think he wants to kill him?"
by Lizzi K March 31, 2006
Get a You-Know-Who mug for your dog Georges.
Aug 11 Word of the Day
A phrase to describe someone who is cognitively degenerating. Synonym of "going off the deep end". Can have varying degrees of severity.

Reference to the song "Hey You" by Pink Floyd. The line "and the worms ate into his brain" makes no sense in an otherwise linear and literal narration throughout the lyrics.
"My boyfriend has a total case of brain worms. He told me the cat was bugged so the Feds could listen in on us having sex..."

or

"You totally stumbled over that entire sentence. Can't speak English all of a sudden? What, do you have brain worms?"
by _Jez_ October 03, 2009
Get a brain worms mug for your brother-in-law Abdul.
2
A person, usually an acquaintance, who you find completely detestable. The mere mention of their name is enough to fill you with a feeling of dread, while an encounter with this person inevitably leaves a cloud of misery hanging over an otherwise pleasant day. This term is derived from a common reference to Lord Voldemort from J.K. Rowling's Harry Potter series.
"I bumped into You-Know-Who the other day...that basically ruined my week."
by Bumpalicious February 06, 2010
Get a You-Know-Who mug for your coworker Manley.
3
The Dark Lord, y'know, the one who doesen't have a kickass mace and a ring fetish...

"You know, I see the oppurtunity for a union here..." - Lord Voldemort (AKA "You Know Who", or "The Dark Lord") to Sauron (AKA "The Dark Lord") and Darth Vader (AKA "The Dark Lord")
by Alexander Girard December 31, 2005
Get the you know who neck gaiter and mug.
4
Dick Trickle, a very unsuccessful NASCAR driver (in SportsCenter terminology). Probably started because his real name is too obscene to say on cable TV.
"Jeff Gordon won his third race this year, and you know who finished his best race of the season in 37th place." -ESPN anchor

Fred: "Doc, I think I caught an STD from this dirty whore I nailed last weekend."
Doc: "Hmmm...what are your symptoms?"
Fred: "I've got an itchy red rash, it burns when I pee, and I've got some real nasty you know who."
Doc: "Dick Trickle, eh? Yep, looks like a classic case ofherpegonnosyphiltitis to me. Bend over, we're gonna have to do a rectal examination."
Ricky Martin: "Giggidy giggidy!"
by Nick D July 13, 2004
Get a you know who mug for your mate James.
5
A unique individual with a ketchup/postit note/broncos fetish. Usually wears wrangler jeans and a white tshirt. May become angry when it reads things like this written about itself.
When did you know who get here and what brand of jeans is he wearing?
by whodoesthisremindyouof January 25, 2003
Get a youknowwho mug for your dog James.
6
a pronoun used to say something about your crush without saying their real name
Raul: Guess who's behind you.
Hugo:Who?
Raul: jasmi-
Hugo: Say "You Know Who" you moron!
Raul: k...
by dark_avenger877 March 21, 2019
Get a You Know Who mug for your barber Manafort.