The person who is called a loser because they are surrounded by stupid people.
A smart person who has both technical and social skills. Not to be confused with nerd who has technical skills but only has those technical skills because he has the time from not having friends or any form of a social life.
Geek (18 year old guy) - Dude! Did you hear that Jake just finished finding a buffer overflow exploit in Google Chrome before he went to the movies with his friends?
Nerd (18 year old guy) - Mommy! I just found a buffer overflow exploit in Google Chrome! Now where is my warm milk and bed time story god dammit!
a person who honestly could not possibly care less what is "cool" or what people think about them.
If they like something that no one else is interested in (books, tumbler, doctor who) they will proudly display and talk about those things.
Not to be confused with a hipster... Hipsters try too hard.