I had a very amusing convo with keyne about this. A lot of the words in the pamphlet are clearly related to or derived from Yiddish, and it's full of FERSH- words (FERSHPRITZ'D, FERSHMEER'D, FERSHTICKED), but it does not include FERSHLUGGINER. I concluded that FERSHLUGGINER must have been one of the words that Don Knuth made up in his early MAD Magazine contributions. keyne assured me that yes, FERSHLUGGINER really is a real word even if it doesn't appear in "Quaint Idioms, &c."