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Refers to the yaoi pairing between Hibari Kyoya (note, this is last name first, first name last basis. Japanese names.) and Tsunayoshi Sawada in the Katekyo Hitman Reborn! fandom. Fangirls use 18 to refer to Hibari and 27 to refer to Tsuna.

Although this pairing is one of most popular pairings in the fandom, it is not canonical-not as much as, persay, 6918 (Mukuro X Hibari), D18 (Dino X Hibari), 5927 (Gokudera X Tsuna) or R27 (Reborn X Tsuna). {8059 is one of the most popular AND canonical pairings in the fandom...but this is about Hibari and Tsuna here. Not Yamamoto and Gokudera}.

With this pairing (and almost every other Tsuna-centric pairing in the Reborn! fandom), Tsuna can almost always be found as the uke (bottom). Because of that, it is suggested that Tsuna should never top Hibari, lest the fangirl mob lynch the offender.

When writing 1827, fanfiction authors tend to make Hibari as OOC as possible, while Tsuna becomes an attention whore. Contrary to the definition above, both 1827 and 6927 are not hot, since 6927 involves raep-even though if viewed in some lights, it can be found more canonical than 1827...while 1827 is just a smashing of the two most popular characters in Reborn!.
FANGIRL 1:I like 1827 because it involves two of my favorite characters, Hibari and Tsuna, in a yaoi relationship. *squee*

FANGIRL 2:NUUUUU! 1827 sucks because Hibari should be paired with Mukuro! 6918! *RAGE!*

FANGIRL 1: ...
1827 by gracefulsunshine June 14, 2011
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A girl who does ballet and only talks about ballet. Her schedule is filled with dance classes which does not allow her to do any other activity.
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"Yeah, she's kind of annoying. All she ever talks about it ballet."

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I had a trucker's tan after driving for 10 straight hours on a sunny day.
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British slang for a scientist or technical expert, esp . when the speaker is not certain of the expert’s specific field of study. Not necessarily derogatory, but typically used by persons without a technical background. In the US, the equivalent would be “egghead”, “squint”, or “geek.”

Origin of the word is unknown. Started sometime in World War 2. Given the typical evolution of British slang, could easily have started because what these experts did was confusing or “baffling” to the common person.
According to the boffins downstairs, the murderer used a serrated blade.
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Pee Calculus

When you have to pee in a movie but don’t want to miss anything, and must do the following mental equation: will the amount I have to pee cause enough discomfort to diminish my attention capacity for the remainder of the movie to an extent which is greater than the amount of the movie I would miss by making a mad dash to the restroom.
I saw Satantango last night, wonderful film but by the 5th hour I had to start doing pee calculus.
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