This is street slang for the slang word sheezy. Because Sheezy is not hood enough for most people now, it must be hacked up and the last part of izzle be added to it. This is a doubble slang also known as a duce matoose. It originated in New Orleans 3rd Ward ProJacts. And was made popular by Lil Mayne.
Yo Fo Shellions yO! No Dogg I takes Dat Back I Means FO Sheizzle!!! Like a big old bizzle my squizzle tizzle rizzle fizzle pizzle dizzle! We OUT!