Geek
The definition of geek has changed considerably over the years. Below are some definitions of the word "geek", in order from oldest (and most archaic) to newest. All but the first are still in use.
A person who swallows live animals, bugs, etc., as a form of entertainment at fairs etc. This often included biting the heads off of chickens. The Geek would usually perform in a "geek pit."
A derogatory term for one with low social skills, often with high intellegence. It is theorised that many of these people have Asperger's syndrome.
A person who is into technology, especially computing and new media. Comparable with the classic definition of hacker.
A person with a devotion to something in a way that places him or her outside the mainstream. This could be due to the intensity, depth, or subject of their interest.
There are many varieties of geek. The computer geek is best known, but every field of academia and many areas of culture have their geeks. There are politics geeks, geography geeks, geeks of the natural sciences, music geeks, history geeks, linguistics geeks, ham radio geeks, public transit geeks (metrophiles), anime and manga geeks (otaku), Star Trek geeks, geeks of many colours, genders, and styles.
see also: nerd, otaku, anorak, geek code, hacker