Stating that you are "for sure" going to do something. It is definate and without a doubt (that is why it is stated twice in a row).
Known from the character Seth in the popular teen movieSuperbad, where he tells Jules that he will "for sure" buy alcohol for her party.
"Yeah we're going to the partyfo sho fo sho. We're going to the party fo sho."
By Modesta
Fo Sho Fo Sho
a girl (or guy i suppose) that is known for being easy. So easy, in fact, that you will "for sure" ("fo sho") be getting laid by them. Also known as a slut.
Dude, i'm so stokedto go out with Suzy tonight; she's a fo sho fo sho!
It is said in the tv show Gangland when Do was describing a way to do a hit.
"We had a, uh two guys, we called them Double Trouble. One person would hit you in the body, which would drop you, and the other person would put the what we call the fo' sho'."