1) the extremely slang/ghetto way of saying "for sure."
2) what those people who always talk in a mixture of southern and ebonics when they talk to sound really cool use in place of "for sure."
boy: hey, do you want to go to the mall later?
girl: fo shante!
"southern guy" from the north: oh maii gawd, dis be lyke, rull kewl.
"southern girl" from the north: iy no, fo shante!!!!!