I originally saw this question here, and it made me wonder.
- I've never heard it before
- It looks like a reasonable sounding construction
- it's not in any online dictionary
- it has a google score (as of this moment) of 1060 hits
- ...but most of those hits are about "Is 'nerdiosity' a word?"
- if enough people start using it in a consistent manner then it might be considered a 'real' word.
- I think 'nerdiness' is the appropriate existing term for the expected concept (gscore of 354,000), but that's kinda nerdy to point that out.