1. The spelling of the word god with the letter D omitted with an exclamatory WHAT!
2.An alternative to using the word "god", sometimes used with a shallow fear of seeming sacrilegious in the eyes of the "almighty".
However, the practical use of the word is comedic more than anything..
Typically used only at the end of a statement, the origin is unknown.
I saw one girl puke in another girl's mouth
I Swear to G.O.Whuuut!!!!
G.O.What! I hate math tests
You better hope to G.O.What that I get my skrill before tuesday sucka