Yahoo Answers attempts to define these oft-used words.
“Nerds are people of above-average intelligence who place little importance on their appearance.”
“Back in the day, geeks worked at carnivals, and (according to the dictionary) ‘bit the heads off live chickens.’ Thankfully, the term now has a different connotation. Like nerds, geeks are smart, but they tend to focus more on technology…These are the people you make fun of in high school and later work for as an adult.”
“Dorks are ‘stupid’ people. And to make matters worse, dorks assume they’re cool.”