of the word geek
is varied. Geek-n. Gék.
Some say it originates from the circus. Sideshow performers were often called Geeks, refering to their weird acts, like the oft cited decapitation of chickens with the teeth. This originates from the Low-German Geck, meaning stupid, weird, or not normal.
The other possibility of origin is from the ancient greek gekas, meaning stupid, not to be confused with the honorable congressman. In this way, geek is similar in orgin to the word cynic.
This has of course come to mean a socially inept computer guru. The modern meaning of geek is very thoughly analyzed.