a)An expression used when impressed, overwhelmed, shocked. Similar to "wow!" and "Oh golly-gosh!". Usually followed by an exclamation mark (!).

b) The urine of a gangster.
a)
Girl: "Wanna get lucky, little boy?"
Guy: "Gee Wizz! It's my lucky day today!"

b)
The carpet was soaked with gee-wizz.
by The Tangoman October 24, 2004
Get the gee wizz mug.
The art of combining the phrase "OMG", or, to frequent users "Oh Em Gee" with the magical, oldschool quip, "Gee-Wizz!". Rolled off the tongue beautifuly, in the poetry that is "Oh Em Gee-Wizz!".
Person #1 : Did you know I'm skilled in the art of badger watching?
Person #2 : Oh-Em-Gee-Wizz!
by Flight of the Sparrow Hawk November 10, 2009
Get the Oh-Em-Gee-Wizz! mug.