Some are rarely used anymore and possibly obsolete, but here is my list of interesting, unique and uncommon words.

Think about how you might use one today!

Ad Nauseam	To a sickening or disgusting degree.
Agog	Excited and eager to know more or see more.
Bafflegab	Confusing, incomprehensible, or generally unintelligible pretentious language, especially bureaucratic jargon; gobbledegook.
Blatherskite	One who talks foolishly at length (or blathers on and on); rambling nonsensical or inconsequential talk or writing.
Borborygmus	the sound of a rumbling stomach; the movement of fluid and gas in the intestinal tract.
Bovine	Having qualities (such as placidity or dullness) characteristic of oxen or cows.
Caperlash	Abusive language; to scold.
Chockablock	Very full or crammed full with people or things; brought close together; crowded; jammed.
Churlish	Resembling a churl; vulgar; marked by a lack of civility or graciousness; surly; boorish; rude
Dolosity	Deceitfulness; having hidden malice.
Drivel	Nonsense; boring and unnecessary information; talking stupidly and carelessly; slobbering, drooling or saliva spilling from the mouth or mucus draining from the nose; twaddle, blather, foolishness, gibberish, babble; talking childishly or foolishly; ideas, statements or beliefs that are silly or not true; meaningless talking or thinking.
Estival	Pertaining to summer.
Feinschmecker	A person who appreciates, enjoys and knows a lot about good food; a gourmet.
Finial D’arbre	A Christmas tree topper.
Flapdoodle	An idea, something said or written, or behavior that is silly or stupid; nonsense.
Foozle	To bungle or botch an attempt at something; play clumsily (i.e. in golf).
Frabjous	Wonderful, elegant, superb, joyous, delightful, delicious.
Gallimaufry	A hodgepodge; confused medley; jumble.
Gambol	To frolic or skip about, as in dancing or playing.
Grame	Anger, sorrow, harm, misery.
Honeyfuggler	A person who deceives, swindles or cheats someone by talking to them nicely, sweet-talking them, or by using flattery.
Hugger-mugger	In a confused, untidy way that lacks order; secretive or clandestine; disorder or confusion.
Illimitable	Incapable of being limited; limitless; boundless.
Jejune	Behavior that is naive, simplistic and superficial; without interest or significance; dull; insipid; juvenile; immature; childish; lacking knowledge or experience; a lack of rewarding or satisfying substance.
Jobbernowl	A Numskull; a Nincompoop; a Block head; a blockish or stupid head; a ludicrous term for the head, usually connoting stupidity.
Joie de Vivre	(pronounced zhwaduh-vee-vruh) “Joy of Living;” a zest for life; a delight in being alive.
Lethologica	The inability to remember a particular word or name; sometimes called “tip of the tongue” syndrome.
Logorrhea	Incessant, wearisome or compulsive talkativeness.
Nugatory	Useless; futile; of no value or importance.
Omnium Gatherum	A collection of miscellaneous people or things.
Parsimonious	Unwilling to spend money, use resources or use a lot of something; stingy or frugal.
Pecksniffian	Falsely moralistic; holier-than-thou; hypocritical; insincere; sanctimonious.
Phylactery	Two small, square, black leather boxes that contain Torah verses (Scriptures) written on parchment; in Jewish religious practice, Jewish men 13 years of age and older traditionally wear phylacteries during weekday morning prayers on the left arm or the head (Matthew 23:5); protection.
Perspicacious	Having keen mental perception and understanding; discerning; having a ready insight into and understanding of things.
Poltroon	A coward or craven; an adjective to describe something that is marked by cowardice; sneaky and devious; an idler.
Pollrumptious	Restless, unruly, foolishly confident.
Popinjay	A vain or conceited person, especially one who dresses or behaves extravagantly; a parrot.
Puzzlewit	A stupid person.
Quakebuttock	Someone who lacks the courage to do or endure dangerous or unpleasant things; a coward.
Quidnunc	An inquisitive or gossipy person; a busybody.
Rapacious	Aggressively or excessively greedy or grasping; ravenous; usually in a selfish way.
Repine	To feel or express sadness or discontent; to complain; To be fretful or low-spirited through discontent.
Salmagundi	a general mixture; a potpourri; a miscellaneous collection.
Sardonic	Bitter or scornful laughter; disdainfully or skeptically humorous; derisively mocking; humorous in an unkind way that shows you do not respect someone or something.
Saturnine	A slow, gloomy, moody, mysterious person or thing.
Scurrilous	Making or spreading scandalous claims about someone with the intention of damaging their reputation; obscenely abusive; humorously insulting.
Sepulchre	A building or room where a dead person is buried; a place of burial, such as a tomb, grave, vault, or mausoleum; a receptacle for religious relics, especially in an altar; in the Bible, it indicates a burial.
Sop	A weak-willed or spineless person; milksop.
Spondulicks	Money; cash; a reasonable amount of spending money; spondoolicks, spondulacks, spondulics, and spondoolics are alternative spellings, and spondoolies is a modern version.
Sybilline	Mysterious; cryptic.
Ulotrichous	Having woolly, curly or crisp hair