In a negative way it means that its messed up, wrong, retarded, stupid.
Person 2: Eh I didn't like him. His teeth were "Jank"
This weather is Jank...
Student 1: we have a pop quiz tomorrow....
Student 2: "That's Jank".
often seperated in terms by using "Jank in the good way" or "Jank in the bad way"
It is also reffered to as
a "Male Groin"
I bought this tv its so JANK i hate it..
Your so Jank, in the BAD WAY! now go to hell jank.
your my best jank buddy