A complete fail of a comeback... basicaly... you would use it when you get verbally bitch slapped your face is all red... and you cannot come up with a comeback.
Faggot: You smell bad

Me: Wow... because you said that dis you went from nobody loving you... to having a small squirl start to love you... oh wait... that squirl just got ran over by a car... your back to nobody loving you...

Faggot: I know you are but what am I?
by balla911 April 16, 2009
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A phrase used to signify that an argument has degraded to an immature level. Used as a response to someone that's turned a friendly discussion in to a personal argument.
Person 1: I hate iphones!
Person 2: I think they rawk. iPhones for everyone!
Person 1: You're a poo brain.
Person 2: I know you are but what am I?
by an0nym0usc0ward February 5, 2010
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A great comeback or a phrase that will wreak havoc. This phrase and be used to simply annoy someone or to say for the heck of it.Also it can be used in a conversation.
1)Ruben:Your a butt cheek

Tom:I know you are but what am I?

2)BOB:I'm going to be Albert Einstein

Rick:I know you are but what am I?
BOB:Beats me it's up to you
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The gen z way of saying haha bitch I won the argument

It is literally the worst comeback of all mankind
You are dumb

I know you are but what am I
by 42069ultimateholdersex April 2, 2021
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Knowing or presuming someone as a member of the lgbtq+ community. Commonly used when commenting on a character of whom many head cannon as queer. Also present in the “homophobic dog” meme lore.
by ivyisliving August 5, 2022
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A term used as a greeting, an insult or comeback, a conversation filler (to fill an awkward silence) and a game by adding a word to the sentence. Coined by Cameron, also known as Camen bu in March 2013. Also used as "I don't even know you!," this version is generally when spoken by really white people.
Greeting:
Person 1: Hey Bob, how you been?
Bob: I don't know you!

Insult/Comeback
Person 1: Bob, that was a terrible speech.
Bob: Bro, I don't care what you think, I don't even know you!

Conversation filler (fill an awkward silence)
Person 1: Bob, will you go out with me?
(Awkward Silence)
Bob: I don't know you!

Game
Person 1: Bob, I don't know you!
Bob: I really don't know you!
Person 1: I really don't even know you!
Bob: I really totally don't even know you!
Person 1: You win Bob.
by StoogeKebab June 9, 2013
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