The more I think about it, the less I like my own idea. The dictionaries available on the net now are great resources, even if they are a bit thin on technical detail. That kind of technical detail is exactly what Wikipedia/Nupedia are designed to create, and splitting the project further will surely result in duplication of effort and less cross-linking. Furthermore, it reinforces the distinction between "dictionary" and "encyclopedia" which I still see as an artificial one.
Here's another suggestion: once we get version 0.92 of the Wiki software, Cliff promises us parentheses. We can recommend that information about words themselves be placed in pages like "Mathematics (word)". That page can go into excruciating detail about the etymology of the word, various senses, and usage (perhaps seeded by the now-PD 1913 Webster or the soon-to-be-PD 1928 OED), while the page "Mathematics" treats the subject of the word's primary sense, so that ad-hoc links go to the right place. These primary pages can contain links to the (word) page if appropriate. 0