"You killed it" is what one says to the other who puts an end to a funny joke.

People will be laughing at a certain joke, then someone will try to enhance the humour by adding a witty comment or something(see list below) to get more laughs albeit failing miserably and making the joke not funny anymore.

The most common ways to kill a joke are to tell the joke so often to the point it isn't funny anymore, or to attempt at enhancing the humour by displaying a sarcastic/witty comment, taking the joke literally or stating the obvious.
1. "Why'd the chicken cross the road?"

"Dude, cut it out! You killed it a long time ago, you told the joke so many times!"

2. "why'd the chicken cross the road?"

"to get to the other side"

"hahahahahahahhaah!"

"maybe the chicken needed to go to the bank!"

"(sigh), you killed it."

3. "What's the difference between a pizza and a Jew?"

"A pizza doesn't scream when you put it in an oven!!!"

"Well why would anyone wanna put a Jew in an oven? They're humans too!"

"It's a joke dumbass, you killed it..."

4. "How do you get 4 fags to fit on one bar stool?"

"Turn it upside down."

"HAHAHAHHAHA!!!!! That's a good one eh?"

"Wow, sounds like they must've enjoyed it, huh?"

"You killed it again!"
by Your Username Here October 15, 2009
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Definition You say it whenever Kenny dies in a episode so every episode or if you see someone named Kenny die
by Kenny McCormicc April 6, 2023
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TJ Lavins favorite saying for when somebody wins a challenge
Alright Jonny congats you killed it you can go rejoin the group

Eric you did well but you lost so you have 20 minutes to get your stuff
by Eryone knows its butters! November 27, 2019
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Underneath this definition, there may be an advertisement! It will say stuff like
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Aldo, urban dictionary, your merch is {look at the gif}
by Qwertyuiopasdfghjkllkjhgfdsapo December 17, 2020
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a mob-like expression for the phrase "You will die if you hear my secret"
Guy 1: Duuuude, howdja get that Ipod touch?
Guy 2: i could tell you, but then i'd have to kill you
Guy 1: is that a no?
Guy 2: WTF was that supposed to mean?
Guy 1: you tell me,
Guy 2: NO!
by your best idiot May 23, 2010
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An alternative way to say 'you are too much'. The longer version is 'you kill me'. The use is for when your friends are being extra but you don't really care you say 'OMG you kill' and move on.
Matt: I made out with three guys last night.
Hailey: You kill.
by Nikkolover636 January 29, 2020
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Stan and Kyle use to say this when Kenny gets killed..not so often after season 5,they kinda realise that it happens all the times..
Kenny gets killed by someone.
Stan:oh,my God!You killed Kenny!
Kyle:You bastard!

Then Kennys dead body is attacked by 3 or 4 rats :)
by Digooo February 12, 2005
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