My entry on spelling bees got me thinking about more obscure words, and I had a little session with the dictionary.
logorrhea: Too much language. (Also see: Blogorrhea)
periphrasis, periphrastic: speaking around the subject rather than to it. Generally, excessive language used when someone is trying not to admit that he agrees with the other side, that he has no ground to stand on, or that he's changing his mind. (Also see: Kerryism)
pleonasm: Insertion of an unnecessary word (Also see: Kerryism)
palaver: This word has a well-known meaning ('empty talk') that certainly has descriptive value in much of the blog-world. But more importantly, it has a second connotation, which is flattery. Political blogs often palaver over their parties of choice, angling (I now learn), for press credentials and other little perks.
spoliation: technically means, alteration of a legal document (as in, Martha Stewart's aborted spoliation of her call log). In blog-land, it might refer to quietly changing a contested post without mentioning it to anyone ('Dude, I realized I was wrong, so before anyone attacked me I just spoliated. No harm done').
nugatory: Technically, a law having little or no force (example: U.N. Resolutions are nugatory). Could also refer to a blog of little influence, or an opinion of little influence (Andrew Sullivan's falling out with the Bush administration over Iraq [Abu Ghraib] is, for instance, completely nugatory).
verbigerate: The often unconscious repetition of certain words or phrases. In the old days, verbigeration was a tic, like saying "um" or "like" too much. These days, many bloggers seem to say "terrorism," "Islamo-fascism," and "Jihadism" three times a minute, in the midst of posts about their cats. But the words are, in the vast majority of instances, just filler, masking a real confusion about the truth of cat-being (which is the only important thing).
deixis: a tricky rhetorical term indicating reference to the context of a spoken utterance ('This speech has been long on questions and short on answers, but bear with me...'). In the blog-world, it refers to comments about the blogger's own blogging. It is a less judgmental word, perhaps, than 'navel-gazing'. Deixis is an instance of self-referentiality; navel-gazing, perhaps, is doing it either gratuitously or too often.
(For more, see the Blogging glossary on Samizdata)
[Update: See this post in aham Brahmaasmi on 'blogorrhea'.]