Gee Whiz
Meaning
An interjection or exclamation of surprise.
Origin
This little term derived in the USA as a euphemistic shorthand for Jesus; in other words, it is a minced oath. That original meaning is largely forgotten by those who use it now, who are in any account fewer than before, as it is now sounds rather old-fashioned. The further shortening of simple gee is still widely used in the USA, although neither version was ever common elsewhere.