Geek
(old definition) A person that 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'
(modern definition) A person that is into technology, especially computing and new media.
A new definition of "geek" is emerging, derived from above, but more all-encompassing: 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.