2. An intelligent person shunned or merely chided because of his or her grades or aptitude at certain subjects. Definition 1 and 2 can be true of a person simultaneously.
3. Likely, due to poular media being considered 'nerdy' by those exceptionally low on the cognitive spectrum. Many self delcared 'nerds' roam the streats. With no social obstacles to overcome these are hardly the nerds they try to emulate and often lack even basic levels of nerdlike obsession. At best a more accurate word for these would be "quirky". At worst a definition would be "An unexceptional and socially active person with a passing interest in Video games, Marvel Superheroes, Harry Potter or Star Wars"
4. Anyone who openly admits to liking Manga or Anime. These are not always true nerds but are genrally considered as such.
5. Anyone who plays D&D. No exceptions.
"Hey, did you play the Battlefield 3 beta?"
"No, I'm not really into videogames."
"Oh... Did you see the Alphas Season finale? Gary went all..."
"I don't really like science fiction... not my thing. did you see last nights game?"
"Sorry, I see no point in continuing this conversation."
"I just built a working personal computer out of redstone in Minecraft! It's capable of running Linux or Windows!"
"Yeah I've read every Harry potter book and seen each movie twice! I know, I'm such a nerd!"
"I have a polyresin replica of Harrys Nimbus 2000 on display next to my Alphonse Elric Armor."
"Hey, Want to watch some Fullmetal Alchemist after we get back from the triathlon?"
"Want to spend hours in a basement playing an endless board game? It's like a video game with no graphics!"
Often mistaken for Geeks, who aspire to become nerds, yet lack the intelligence, and end up giving nerds a bad name due to their poor social skills.
Non-nerds are often scared of nerds, due to their detailed knowledge, and therefore seemingly high levels of intelligence - and subsequently denegrate them as much as possible as often as possible.
Nerds exist covertly within the fabric of society, often choosing to 'nerd it up' in private or in the company of fellow nerds. It is for this reason they are feared the most - unlike geeks, who are easily identified, nerds can only be found out when casual conversation reaches a subject that they like nerding.
Nerd: "Let's bash this nerd"
Nerd: "That'll teach you to go playing with my tesla coil"