I'm a huge nerd, and I used to be afraid to admit it. I'm not afraid anymore, I don't think the word has negative connotations anymore for most people.
The definition I prefer:
An intelligent but single-minded person obsessed with a nonsocial hobby or pursuit
"Never forget what you are. The rest of the world will not. Wear it like armor, and it can never be used to hurt you." - Tyrion. Pretty much sums up how I feel about this.