a crazy person; a gross person; a smart person
The word “geek” is a fairly recent Americanism, derived from the Middle Low German “geck,” which was supposed to a sound crazy people made.
Ironically, one of the geekiest guys in my high school, bless him, had the last name of Goeckel, and everyone called him “the Geck.”
But that's beside the point.
“Geck” became “gek” in Dutch, meaning madman or fool. It found its way into American slang as “geek,” a guy who does really gross and disgusting things in the side show at the carnival. The classic act for the carnival geek was to bite the head off of a chicken.
Eventually the word was used to refer to anyone who was gross or undesirable, be it through lack of hygiene, lack of social skills, or some other repulsiveness.
Recently it's come to imply a certain bookishness or braininess as well, in keeping with the American anti-intellectual tradition. Opinions vary as to whether the braininess causes the repulsiveness or vice versa.
Very recently — in the 90's — the repulsive connotation has receded and the brainy factor has come to the fore. One often hears the word “geek” used in ironic and even complimentary fashion to connote knowledgeability and expertise.
Does this signal the reversal of the aforementioned anti-intellectual strain in American culture?