A derivative of Heads up, this term was widely used(shouted) in the lot before and after Phish shows in order to alarm surrounding bystandards that law enforcement was in the vicinity and to conceal any contraband immediately. It was often used on shakedownwhen an undercover officer was discovered, or a regular officer was on the prowl and somewhat hidden by the general crowd. It was also seen on a popularfan made t-shirt which used a parody of the 7Up logo and read "6 Up, The Uncoola".
Head #1: "6 Up!"
Head #2: "Shit, stash those goo-balls and caps!"
Term adopted from Japanese into the English used chiefly by Japan-dwelling gaijin, meaning to overcome, by will, a deficiency in genkiness, i.e. the degree of being genki, where genki has the Japanese meaning of possessing high degree of health, vitality and/or energy.
Use of this term has nothing to do with being Wapanese if used by an expat living in Japan or when conversing with current or former inhabitants of Japan.
Not to be confused with any of the definitions provided of genk (or any other English language terms adopted from non-Japanese language origin).
Whaddya mean you're not drinking tonight? Genk the fuck up, man! (in this sense, compare harden up, harden the fuck up)