i have always defined nerd in my own mind as someone who is, while at the same time intelligent, also obnoxious about the knowlege that he feels makes him superior to those around him.
a similar word, geek, i define slightly differently: a person who is intelligent, usually unattractive, but, unlike nerds, is not obnoxious about their intelligence.
then there is dork. actually a slang word for 'penis,' i define a dork as a person who thinks he is intelligent but isnt, and is still obnoxious about it.
here is a simpler way to look at it:
these are just my own personal definitions, but feel free to use them as a guideline.Code:intelligent obnoxious nerd yes yes geek yes no dork no yes