EDIT: With your comments:
There will be the following synonyms:
The questions tagged as: sites should be retagged accordingly
The sites will be blocked for usage
I'd argue that force.com sites and site.com are two very different but similarly named technologies. I think more appropriate would be force.com-sites (merging in sites) and site.com tags. Blacklisting "sites" as a general term would probably be a good idea in this situation.
For example: I have extensive experience with force.com sites but I've never so much as seen a site.com page, and the technology used to build them is again drastically different.