Hello Gillin, As a slang word it means either: - a boring and unattractive social misfit . Some times “科学小怪人" or bookworms are called geeks just for their eccentric behavior or that they might seem a bit strange, but you can't use those words as a synonym for " geek". The same goes for people who are good at computers they have been called geeks for their eccentric behavior and their unusual or odd personalities rather than the skill they have. - The word could be also a variant of the Scottish word "Geck" which means "fool". It refers to someone who is departing from his kind , base, inferior or humble.

very good Zsou ... but I have to add it is slang...

as nerd,dork,or wuss but other meaning is master hand,expert ,also high-risk sb good at computers