My personnal definition
Is basicly a fan of a certain thing who has extensive knowledge of that subject or just loves it to death The subject however mst have some mystery to it
Star Wars Geeks-geeks
LOTR Geeks-geeks
TV Geeks-geeks
Then there are geeks who only know about one thing these may be called geeks but they are nerds there is no mystery the merely know
Computer Geeks-nerds
actually best way to seperate the two Geeks like fiction Nerds like nonfiction
here is my map of geeks
fan-fanatic-knowledgable-geek-super geek-uberdork
nerds
knowledable-smart-nerd-way too smart-scary smart-stuffed in locker smart