This is a community. And it's on LiveJournal. LiveJournal is composed of many users, many of which are nerds, and many of which are sluts. Moreover, some are both. And some are nerdsluts, which may or may not mean one who is both a nerd and a slut. Both terms have definitions, and it would make the universe much easier to combine the two definitions to create the definition of "nerdslut". However, the universe can only be made easier ~5.9% of the time, and chances are it means something else. We may know in time.
Or it's whatever you want it to be. Beauty is in the eye of the verbally insecure or something.