A coinage ... combining a number of roughly synonymous Latin stems. Latin flocci, from floccus, a wisp or piece of wool + nauci, from naucum, a trifle + nihili, from nihilum, nothing + pili, from pilus, a hair, something insignificant (all therefore having the sense of "worthless" or "nothing") + -fication.
http://en.wiktionary.org/wiki/floccinaucinihilipilification
