It distresses me beyond measure that I cannot recall where I first read or heard this word. Even a google search failed to turn up one instance. It is not my own coinage, but ever since I read it, or heard it, I use it often, and would like to think that it will one day gain currency. A babblatrice is of course a woman who talks a great deal without saying anything of worth. Very handy, and challenging to those who hate gender-specific words (another reason it should be vigorously espoused). Commenters who may know of its origins, please let me know and I will update this post with an attribution. Offended commenters might like to try coining an equally insulting word which could be used to denigrate babbling males (Chomsky is already taken - sorry!).
UPDATE: by the bye, one can have a lot of fun with the generation of gender-balancing words in the cause of political correctness. The best known of course is Woman-hole (or person-hole) to balance the orthodox and time-honoured man-hole. (I don't know what it is, but one can't say "woman-hole" with the same degree of insouciance as one can say "man-hole".) Another amusing one is the gender-neutral "fishers" to replace "fishermen". It's wonderful watching the facial contortions of TV presenters when they try to differentiate between "fishers" and "fishes" as they read a (politically correctly phrased) fish story. Did the fishes eat the fishes (the normal food chain); or did the fishers eat the fishes (what one would expect, unless the fishers sold the fishes to the fish-shop); or did the fishes eat the fishers (as in the movie Jaws - clearly this would be a big story in the "man bites dog" genre)? Or... did the fishers eat the fishers (cannibalism on the high seas - an even bigger story.)?