Otiose

o-ti-ose (/ˈoʊdiˌoʊs)*
adjective
1. having no practical result or outcome.
Most of our most wonderful desires are otiose at their root; their function being simply giving us something to wish for; and, ultimately, leaving us empty when our wish has been fulfilled. 

Synonyms: empty, futile, hollow, idle, inactive, indolent, ineffective, laggard, lazy, slothful, sterile, superfluous, surplus, vain.

*Though in pronunciation and meaning, this word is very close to the word odious; so close, in fact that I had to triple check to be sure that this was not just a variation in spelling. It's not. A thing that is odious is useless, but also despised. Our feelings about an otiose thing, however, can be neutral or even positive. Indeed, Oscar Wilde might have said that all art is otiose.

Oobleck

oo-bleck (blk)

noun
1. A non-Newtonian fluid made from two parts corn starch to one part water, with unusual physical properties.*
At this point, moving out of the province feels a little bit like running on oobleck. I hope to have a few days, after all is said and done, to just sit and say goodbye to the ocean. It might be a while before I see it again, even if the amazing people that I associate with it might come visit me someday. I wish the Pacific could do the same.
2. A fictional green precipitation in the Dr. Seuss book Bartholomew and the Oobleck.
What would you do if you were stuck in a big puddle of oobleck?

Synonyms: soquid.**

* This shit is something like a solid, but is actually a liquid... it's crazy!
** I know this term was meant to refer to the most delicious Frosty drink/dessert served at Wendy's restaurants, but it accurately describes oobleck as well!

Operatrix

op-er-at-rix (p-rtrks)

noun
1. Same as a female operator/operatress.*
The nurse, who was operatrix of the x-ray machine, would have none of my whining or squirming about.

Synonyms: controller, operator, operatress.

* But it somehow sounds more domineering, doesn't it?
** You can see by the draconian eyes on the girl in the picture that she is a little evil.

Ocarnia

o-car-ni-a (k-rn)

noun
1. An egg-shaped terra cotta wind instrument with a mouthpiece and finger holes.
For the Queen of Fernwood's birthday, I bribed this guy from MySpace to play Happy Birthday on his ocarnia.

Synonyms: hippie flute.

* The ocarina is not just for hippies anymore! This undervalued musical instrument has received a major boost in cultural appreciation through the game Legend of Zelda.

Obsequious

obsequious (b-skw-s, b-)

adjective
1. Obedient or submissive to the will of another in an attentive and compliant, yielding or devoted manner.
Although I love her, the attitude of Jeannie, who gave her name to the TV show, kind of freaks me out. I want to be worshiped by someone whose worship comes as a surprise, from someone you wouldn't normally expect that kind of devotion. The adoration of those who are known for their obsequious romances does little for the ego at all.
2. Characterized by sucking up through obedience and/or flattery.
Obsequious attention always freaks me out because I know there is a hidden motive somewhere.

Synonyms: abject, beggarly, bootlicking, brownnosing, complacent, compliant, deferential, duteous, enslaved, fawning, flattering, ingratiating, kowtowing, menial, obeisant, prostrate, servile, slavish, sniveling, spineless, stipendiary, subject, submissive, subordinate, subserviant, syncophantic, toadying, unctuous.

* Too many love songs portray love as an obsequious emotion. I don't want to be worshiped; I want to be adored.

Oggin

og-gin* (gn)

slang/noun
1. The sea, but just that bit you are closest to.**
There's more to the sea than this oggin you're drowning in.

Synonyms: hogwash, ocean, puddle, salt water, sea, the soup.

* A British slang term that originated in the 1940s as a corruption of the term hogwash.
** Because it just refers to that bit of the sea you are closest to, you can fall in the oggin, but don't talk about the seven oggins; it just wouldn't make any sense.

Oddments

odd-ments (ŏdˈmənts)

noun
1. Something remaining over; a thing not reckoned or included; an article belonging to a broken or incomplete set; a remnant; a trifle; an odd thing or job.
There's a place in the Square for oddments that we paupers call a free store.

Synonyms: debris, leavings, leftovers, legacy, odds and ends, remnants, residue, scraps, surplus, survivors, trash.

Onomatopoeia

on-o-mat-o-poe-ia (ŏnˌə-mătˌə-pēˈə, -mäˌtə-)

noun
1. A word that imitates the sound of the thing it describes.
Simon Soundman likes onomatopoeia too much!

Synonyms: yes.

Obstreperous

ob-strep-er-ous (əb-strĕpər-əs)

adjective
1. Loud and disapproving.
Pam sent me obstreperous messages, when she noticed that none of her favorite words were defined in my blog today.

Synonyms: bitchy, blusterous, boisterous, booming, clamorous, disorderly, loud, loudly fractious, out of hand, piercing, raising Cain, rambunctious, riotous, roaring, roof-raising, rowdy, screaming, strepitous, tumultous, unmanageable, unruly, uproarious, vociferous, wild.

Oferdrencan

of-er-dren-can* (I imagine this sounds something like over-drinking.)**

verb (Old English)
1. To drink excessively with the intention of getting drunk.
Yesterday was a write-off because I was oferdrencan again and got totally befuddled the night before.

Synonyms: gedrincan,*** getting drunk, intemperance, over drinking,

* I found this word in the Old English Thesaurus, which is a kind of online database of neat old words. You can also skim through a print edition on Google Books.
** Any help you can offer with the pronunciation of Old English words would be greatly appreciated.
*** Also a fun Old English word, but not as fun as oferdrencan.
Warning: Over drinking can lead to the following situations: "Das Alles wär nie passiert."