What does shiza name mean and what origin is it from?

"Shizzy" or "The Shizzy" is usually an expression of ones feelings of positive emotion or attitude towards anything, especially when used as an exclamation.

I'm sure it can be used in a negative manner as well.

Positive: "Awe shizzy we won the game!"

Negative: "Awe shizzy we lost the game"