When ketamine and cocaine are mixed together to create a dangerous drug combination (most commonly mixed at a ratio of 1:1).

'Yay' comes from a Spanish word for cocaine: 'yeyo' (also referred to on this site and the film Scarface). 'K' is slang for ketamine and the phrase rhymes with the dangerous weapon 'AK47' - referring to the drugs dangerous and uncertain nature.

The term was first used and created on 05/07/09 in Hyde Park, London, England by a guy 'Mustang D' who incidentally & unfortunately ended up in a festival medical tent due to the effects of a mixture of Yay-K47 and various other narcotics (illustrating the potentially dangerous nature of the drug).

In a very short space of time the term has since become an extremely popular substitute for the previous slang word of the same meaning: 'CK1' (cocaine-ketamine) - due to it's ingenuity. It is currently in use around the South of England but is rapidly spreading around the world due to the extensive use of the Internet and social networking websites.

Official spelling is 'Yay-K47' but 'YayK47', 'Yey-K-47' have also been used.

Buying Yay-K47 from a stranger can be dangerous as it is impossible to truely know the ratio of the mix and whether or not other narcotics are present. Mixing narcotics or any drugs can be extremely dangerous.

The safeguarding of Earth and other worlds from biological cross-contamination (i.e. billionaires with too much time on their hands).

Also known as “planetary protection.” Planetary protection / quarantine “reflects both the unknown nature of the space environment and the desire of the scientific community to preserve the pristine nature of celestial bodies until they can be studied in detail.”

There are two types of interplanetary contamination. Forward contamination is the transfer of viable organisms from Earth to another celestial body. Back contamination is the transfer of extraterrestrial organisms, if such exist, back to the Earth's biosphere.