Basically, crack is silly, intentionally non-serious, and has a high tendency to be extremely crazy and unfounded, such as purposeful OOC-ness or playing on cliches, inside jokes, and/or fanon.

The term crack probably stems from crack as in crack cocaine, as opposed to a crack in a wall. As in, so horrendously unfounded/silly that only one could have come up with it while under the influence of crack.
Ed/Roze and Kagome/Kohaku are my secret crack pairings in the Fullmetal Alchemist and Inuyasha fandom.

Kagome/Sake, Inuyasha/Tessaiga, Inuyasha/Kagome's Seiraa Fuku, Shinidamachuu/Kikyou, Naraku/Kikyou's Ashes, and Jakotsu/Hairpin are also crack pairings - these are all from Inuyasha as well.
by Numisma August 13, 2005
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a now obsolete adjective popular as a business buzzword among yuppies in the early eighties. It described a worker who was very smart and very fast-paced.

This meaning of "crack" was forced out by the drug, crack, in the mid-eighties. Sort of like you can't say "gay" to mean "happy" anymore.
That was a good move to hire him; he's crack.
by Dr. Heywood R. Floyd May 20, 2007
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Another form of cocaine: 2 parts cocaine to one part baking soda, with a little water, heat gently until a precipitate forms: this is your crack
Why do cokeheads think they're better than crackheads?
by urchin May 14, 2003
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I cracked on the shawty Melissa earlier
I'm trying to crack on that one girl right there
by DaWvyBoy November 7, 2019
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The word originates from the Anglo-Saxon term, "crack" meaning fun.

It possibly dates back as far as Old English or the older Scots dialect and is still used today by Ulster-Scots in Northern Ireland.

Borrowed by the Gaelic Irish and spelt "craic", the term has been picked up by UK journalists in recent years and has re-entered the use of the word (Hiberno-English) in mainland UK.

Dublin journalists in the 1970s frequently spelt the word as "crack" in written articles.
What's the crack?
Aye it was good crack!
To crack a joke
by GoonerGary May 12, 2007
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1. freebase form of cocaine, generally smoked in a crackpipe

2. the crevice between one's butt cheeks.
"The Customs officer stripsearched Oprah and found forty pounds of crack."
by Joe Bone March 14, 2005
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A small, illegal program who's sole purpose is to trick another program (by editting, imputting a registration key, or some other method) into thinking it has been registered.
by Invalid H. User April 24, 2003
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