Bootleg

A term derived from the English "bootleg" which originally referred to something (usually an alcoholic drink) hidden down the leg of a boot. Later referred to "alcoholic products sold or transported illegally" and eventually any illegally sold or obtained good.

In current slang it is a term linguistically opposite to "legit". By association with the poor quality of "knockoffs", it refers to anything poorly made (1). By extension, and through its relationship with legit, it can also refer to something unfair (2).

1. "You made this test? And it has typos? Man that's bootleg."
2. "I told you to start your drill ten minutes ago; now you can finish it at lunch detention." "Man, that's bootleg!"