There are many terms from classic and modern SF that remain unresearched, and the Historical Dictionary of Science Fiction will be continually updated, especially as additional resources are put online. Boing Boing is syndicating new entries from the HDSF on a regular basis. (Read the series introduction.)
Fans of Philip K. Dick will be familiar with the word conapt, which is simply an apartment—typically, though not necessarily, a small and depressing one in an city. Dick, who apparently coined it, used it in a wide range of his books and stories, including Ubik, The Three Stigmata of Palmer Eldritch, Do Androids Dream of Electric Sheep?, "We Can Remember It For You Wholesale," and "Minority Report," among many others.
There's nothing particularly science-fictional about the concept, apart from its association with the dystopian urban scenarios found in a certain strain of SF. And since the HDSF, as a matter of policy, tends to avoid including terms that are used chiefly by a single author, the entry for conapt was kept in a draft folder. But it's not an obscure term in the Dick canon, and critics of his work discuss it as symbol of the alienation felt by many of his characters. And it turns out that the word is rather more widespread than just Dick; others who have used it include Keith Laumer and L. E. Modesitt, Jr., who are hardly minor writers. And non-PKD authors were using it as far back as the 1960s, and continue to do so. Thus, it seems entirely appropriate to elevate it from the draft folder to the dictionary itself.