Coined from the hit movie "Mean Girls" by the excellent actress Rachel McAdams. It can mean many things, either friendly or non. Mostly used as a greeting, or as a burn, bitch. It's a flexible saying, but be sure you're friendly before using in a joking manner, it could be offensive as well.
Jeanean: "Hey Kylie!"
Kylie: "Boo you whore! what are you up to girl?"
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Geneva: "I'm so upset! My boyfriend David broke up with me!"
Olivia: "Boo, you whore-- get over it!"
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Barbie Barbara: "Damn, I'm hot in my A&F jeans."
Emo Emily: "Boo, you fucking whore! Get over yourself, cake face!"
Kylie: "Boo you whore! what are you up to girl?"
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Geneva: "I'm so upset! My boyfriend David broke up with me!"
Olivia: "Boo, you whore-- get over it!"
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Barbie Barbara: "Damn, I'm hot in my A&F jeans."
Emo Emily: "Boo, you fucking whore! Get over yourself, cake face!"
by Jeanean_The_Hottie January 13, 2007