Geez is short for Jesus. When something an accident happens, such as someone falling, people often say something such as, "Jesus that hurts." Some people (mainly Christians) believe they shouldn't take the lord's name in vain, thus have shortened it to geez, even though, it's technically just as bad.
Geez Examples
- Geez, I forgot my homework.
- Geez, can't believe I'm gonna be late to work again.