It's a more calmer way of saying the curse word "shit", used in various expressions and ways .
Or another way of saying the slang "fo sho" to "fo shizzle"
Girl 1: Oh shizzle I just left my food..
Mom: Hey?! You know aren't allowed to curse until your thirteen
Girl 1: Mom chill, I didn't even say a curse word I just said "oh shizzle" geez
Mom; Oh! Okay..
OR..
Boy 1: Yo, you headin' to Drakes concert too?
Boy 2: Fo shizzle // Fo sho
Boy 1: Aightt see u there "Boy 2"
Money.
Alone.
Kind.
Appreciative.
Young.
Lovely.
Amusing.
Happy.
Girl 1: Hey do you know that Makaylah girl?
Makaylah: Well I am Makaylah
Girl 1: Oh..
Makaylah: Uh.. were you trying to gossip about me?
Girl 1: Well..
Makaylah; You don't even know how I look and your gonna.. okay, it's fine i dont even care a but
Girl 1: ..