ragmatical (P) - wild, ill-behaved This obsolete word has good rhythm...no reason to not use it other than no one will know what you're talking about. "Your kids are ragmatical"...I can hear myself saying that but then dodging the meaning when the parent asks what I just said. That's one of the perks of sesquipedalianism: you can obfuscate the meanings of words that slip out of your mouth heedlessly. The Fifth Amendment still applies at the Society.
sangfroid - cool composure; literally: cold blood A perfect example of this trait is found in one of the champions of football, Joe Montana. His fellow players said that when the game was on the line, good ol' Joe was as cool as a cucumber. It's as though he had no doubt of victory. Nikhedonia was in the air.
tacenda(P) - things not to be mentioned With family Christmas just behind us, I hope we all remembered the tacenda that could blow up the party.
ucalegon(P) - neighbor whose house is on fire How does a word like this come into being. English never ceases to amaze me.
ultracrepidate - to criticize beyond one's field of knowledge Since everyone has an opinion on most subjects but most people have comprehensive knowledge on just a few, that makes most of us ultracrepidarians(p.224).
valetudinarian - concerned about health; ill-health As opposed to hypochondria where the implication is imaginary ailments.
wanweird(p.26) - an unhappy fate This word captures its meaning...I've never heard it used, alas.
xanthodont(P) - one with yellow teeth If you're gomphipothic(p.72) - attracted by the sight of a lovely set of teeth - you probably steer clear of a xanthodont.
yahrzeit(P) - Jewish remembrance of the first anniversary of someone's death There aren't many sesquipedalian 'y' words...it's a neologism opportunity! Wordsmiths should get busy! CHE has a good one of course: yazzihamper(p.108) - a disliked or dislikable person....New Year Resolution: I WILL find an occasion to use "yazzihamper" soon!
zelotypia(P) - excessive zeal in carrying out a project This can be both good and bad. Unfortunately, the zealots of history have tended toward megalomania and the world has suffered.
aboulomania(P) - pathological indecisiveness You don't want to go to dinner with an aboulomaniac...they'll drive you nuts just trying to pick something from the menu.
bouleversement - an upset or upheaval; ruin A good word to use when discussing financial crises or wars.
cephalonomancy(P) - divination by boiling an ass's head In a heated argument with an obtuse opponent, wouldn't it be rapturous to see smoke issuing forth from his ears? Could that be called cephalonomancy?
dziggetai(p.110) an ass-horse native of asia; in appearance between an ass and a horse. Hmmm...here's another multi-use term with human applications, especially during a billingsgate(p.96).
eccedentesiast(p.129) - a person who fakes a smile, especially on TV We've all done it. Starting with family photos as kids and progressing to adulthood at family reunions. Now with "smart-phones" we've developed the canned smile of our "best side" that can hold up to multiple potential facebook postings. Be sure to whiten your teeth before your 50th high school class reunion - it'll make a big difference in the posed shots.