Lying awake thinking about self-descriptive words, I thought of flibbertigibbet as being an accurate one. But who now uses, or even knows, this term? M-W says it's from Middle-English flepergebet, a thoroughly Germanic-sounding word if ever there were one. Who can supply a bit more etymology?

Michael Quinion can, on World Wide Words.

Quinion makes it sound French in origin, and, as in the Shakespeare reference,similar to dwarf in its malevolence, as I noted in the "Midget" thread. A "Grimm" development!