Someone who doesn't fully relate to one of the three specific categories of a jock, geek, or nerd. Rather, they exhibit several interests in each, thus creating some confusion as to which of the three they best relate to.
Jeekerds tend to care more about their social lives and appearance than typical geeks or nerds, but will still go into spasms of "controlled" excitement when their favorite Anime or Sci Fi show is on.
Jeekerds may suddenly disappear from time to time, and reappear without warning. Where they go or what they do could be anyone's guess.