Synonym for "wow". Alleged etymology: A way of saying "Jesus!" without being accused of swearing. More often used as a negative exclamation than a positive one.
Gee wiz, what have you gone and done with your hair?
To study, particularly in preparation for a test or exam. (Used in South Africa, this word has now largely gone out of fashion amongst English kids, but is still used often by Afrikaans kids.)