Please anyone tells me what geek means? Thanks.
It means ' stupid ' as an American slang
Thanks Whl626! I found this word in the Today's Poll section of www.virginstudent.com. But I don't really catch why there is such a poll, I make a copy of that:

Are you a geek?
Definitely – geek and proud!
Yes – but don’t tell anyone. It’s embarrassing
No – I wouldn’t call myself that
No way – geeks are, er, geeky
What’s a geek?
606 response(s)
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In the old days, before Bill Gates, the word "geek" was used in USA high schools as a way of teasing strange looking kids. If a kid had a neck like a chicken and teeth like a horse, they would usually be called a geek. Not by everyone, only by the cruel kids.

The word "nerd" was a similar word. Nerd was the word that they used to tease the type of kids who were in the chess club, always carried many pens and pencils in their shirt pockets, and performed higher maths for in their spare time fun and self-amusement.

Bill Gates was teased in school as both a geek and a nerd. When he made it onto the cover of TIME magazine in 1984 with the caption, "Revenge of the Nerd!", everything changed. Today people use the word geek and nerd almost interchangably, to mean someone who is extremely focused and knowledgable about a specific topic, usually in the sciences. The word is now used by people, with pride, to describe themselves. Five years ago you would often hear the phrase, "computer wizard", now you hear, "geek", to mean to same thing.

geek (gêk) noun
1. An odd or ridiculous person.
2. A carnival performer whose show consists of bizarre acts, such as biting the head off a live chicken.
[Perhaps alteration of dialectal geck, fool, from Low German gek, from Middle Low German.]
- geek´y adjective

nerd also nurd (nûrd) noun
1. A person regarded as stupid, inept, or unattractive.
2. A person who is single-minded or accomplished in scientific pursuits but is felt to be socially inept.
[Perhaps after Nerd, a character in If I Ran the Zoo, by Theodor Seuss Geisel.]
- nerd´y adjective
Word History: The word nerd and a nerd, undefined but illustrated, first appeared in 1950 in Dr. Seuss's If I Ran the Zoo: "And then, just to show them, I'll sail to Ka-Troo And Bring Back an It-Kutch a Preep and a Proo a Nerkle a Nerd and a Seersucker, too!" (The nerd itself is a small humanoid creature looking comically angry, like a thin, cross Chester A. Arthur.) Nerd next appears, with a gloss, in the February 10, 1957, issue of the Glasgow, Scotland, Sunday Mail in a regular column entitled "ABC for SQUARES": "Nerd-a square, any explanation needed?" Many of the terms defined in this "ABC" are unmistakable Americanisms, such as hep, ick, and jazzy, as is the gloss "square," the current meaning of nerd. The third appearance of nerd in print is back in the United States in 1970 in Current Slang: "Nurd [sic], someone with objectionable habits or traits. . . . An uninteresting person, a 'dud.'" Authorities disagree on whether the two nerds-Dr. Seuss's small creature and the teenage slang term in the Glasgow Sunday Mail-are the same word. Some experts claim there is no semantic connection and the identity of the words is fortuitous. Others maintain that Dr. Seuss is the true originator of nerd and that the word nerd ("comically unpleasant creature") was picked up by the five- and six-year-olds of 1950 and passed on to their older siblings, who by 1957, as teenagers, had restricted and specified the meaning to the most comically obnoxious creature of their own class, a "square."

The American Heritage® Dictionary of the English Language, Third Edition copyright © 1992 by Houghton Mifflin Company. Electronic version licensed from InfoSoft International, Inc. All rights reserved.
I think it is used on the negative sense. If it means a computer wizard, there is no need to feel embarrassed right ? Well, this is my understanding from some American movies.
Emotion: smile Thanks a lot Trellis, that's really really interesting!
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I see , Whl626, thank you, I really like the forum!
In most movies you will see the word "geek" used in a negative sense.
The movie industry is run by fat, old guys in suits who are 20 years behind the times.
I am sure that you will see "geek" used in less negative ways in new films soon.

All three of the "Lone Gunmen" in the show, "The X Files", are geek and nerds.

Also, I think that people calling themselves "geek" is their way of claiming and redefining the word as their own word. This is the same as when homosexuals use "***" and some black people use "***". They are then able to defuse the hurtful sting in the words, by using them in an altered and often humorous way about themselves.

I do not say "***" or "***", but I understand why they do.