also ~z
1.
People sometimes say ~ in order to express a strong reaction to something or to introduce a remark or response. (AM INFORMAL)
Gee whiz, they carried on and on, they loved the evening.
EXCLAM feelings
2.
You use ~ to describe something that is new, exciting, and impressive, but that is perhaps more complicated or showy than it needs to be. (mainly AM INFORMAL)
The trend now is towards ‘lifestyle’ electronics–black, shiny gee-whiz things that people like to own.
ADJ: ADJ n