obsession.noun,.plural.obsessions
compulsive-preoccupation with a fixed.idea or an unwanted feeling or emotion, often accompanied by symptoms of anxiety; a compulsive, often unreasonable.idea or emotion
obsessional.adjective
obsessionally.adverb

offhand, offhandedly.adverbs
without preparation or forethought; extemporaneously
offhanded.adjective
performed or expressed without preparation or forethought; extemporaneous
offhandedness.noun

on the spot
under.pressure or attention; in a pressed position 

on the one hand.adverb
on the other hand.adverb
used to present factors for and against; as one point of view; from one standpoint and another point of view from another standpoint; contrastive; instead; contrariwise, on the contrary, to the contrary; rather; vice versa; in compensation

oblique.adjective
slanted; indirect or evasive (oblique political maneuvers); devious, misleading or dishonest (gave oblique reasoning in his efforts to prove the evolutionary theory); not direct in descent; having a slanting or sloping direction, course or position; inclined
Mathematics:.in mathematics, oblique refers to designating.geometric lines or planes that are neither parallel nor perpendicular
obliquely.adverb
obliqueness.noun

openminded.also.open-minded.adjective
having or showing receptiveness to new and different ideas or the opinions of others (being of an open mind, she progressed quickly in learning what was correct through researching and proving:.1Thessalonians 5:21); broadminded; compare close-minded
openmindedly.adverb
openmindedness.noun

openhearted.adjective
frank; kindly; straightforward; responsive in emotions such as compassion
openheartedly.adverb
openheartedness.noun

open.adjective
affording unobstructed entrance and exit; not shut or closed; if you open something such as a door, window or lid or if it opens, its position is changed so that it no longer covers a hole or gap; 
an open window (a door needed to be forced open because it was stuck); 'open up' means the same as open; if you describe a person or their character as open, you mean they are honest and do not want or try to hide anything or to deceive anyone (he had always been open with her and she was thankful his character was that way; she has an open, trusting nature); if you are open to something that means you are willing to listen to it and consider it; if you say that a fact or question is open to debate, interpretation or discussion, you mean that people are uncertain whether it is true, what it means or what the answer may be;
open, opened, opening, opens.verbs
transitive verb use.to release from a closed or fastened position; if you open a computer file, you give the computer an instruction to display it on the screen; they have now opened to road to regular traffic; to remove the cover, cork or lid from; to remove the wrapping from; undo; to unfold so that the inner parts are displayed; to spread out (open a book or a newspaper); to get something going; initiate (time to start on my studies); to commence the operation of (start up the tractor)
intransitive verb use.to become open (the door opened slowly from the wind through the open window); the countryside opened in front of us as we drove over the hill)
openly.adverb
open.noun
an unobstructed area of land or water; the 'open' is the outdoors (camping in the open with trees all around); having interspersed.gaps, spaces or intervals (an open weave shawl); not legally repressed (an open caring society)
openness.noun
open waters; the open countryside; an open roofed car to let the sunshine in; 
open one's eyes.idiom
to become aware of the truth of a situation

out and away.adverb
by far (she's out and away the best swimmer on the team)

out-and-out.adjective
complete; thoroughgoing (an out-and-out mechanic)

out of the frying pan into the fire
clear of one difficulty only to fall into a greater one; from a bad situation to one that is worse

out of sync.adverb
not in synchronicity

out of turn.adverb
not in due.order of succession; play out of turn (it wasn't his turn to bat the ball); at a wrong time or place and perhaps in an imprudent.manner

outmoded.adjective
not in fashion; unfashionable (outmoded attire); outmoded ideas; no longer usable or practical; obsolete-(outmoded machinery)
outmode, outmoded, outmoding, outmodes.transitive verbs-
to cause to become unfashionable or practical

out.adverb
on a direction away from the inside (went out of the office; I going out for a walk); in baseball, so as to be retired or counted as an out (he grounded out to the shortstop); used in two-way radio to indicate that a transmission is complete and no reply is expected (over and out)
out.adjective
exterior; external (the out surface of a ship's hull); outgoing (the out doorway or exit); no longer fashionable (her clothes are out of fashion)
out.preposition
forth from; through (he fell out the window); beyond or outside of (out this door is the garage)
out.noun,.plural.outs
one that is out (she is not home, she is out for awhile; the window was my only out; in baseball, a play in which a batter or base runner is retired; the player retired in such a play (three strikes and he was out)
out, outed, outing, outs.verbs
intransitive verb use.to be disclosed or revealed; come out: Truth will out
transitive verb use in sports, to send a tennis ball for example, outside the court or playing area; to have been knocked unconscious
on the outs.idiom
not on friendly terms; disagreeing

outer.adjective
located on the outside; external; relating to the body or its appearance rather than the mind or spirit

obscene.adjective
offensive to accepted standards of decency or modesty; coarse; inciting.lustful feelings; lewd; offensive or repulsive to the senses; loathsome
obscenely.adverb
obscenity.noun,.plural.obscenities
the state or quality of being obscene; indecency, lewdness or offensiveness in behavior, expression or appearance; something, such as a word, an act or an expression, that is indecent or lewd; something that is offensive or repulsive to the senses ("What had once been a gentle hill covered with lush grass turned into a brown obscenity of bare Earth and smoke."....Tom Clancy)

obsequious.adjective
full of or exhibiting servile.compliance; fawning (the waiter must have come from a slave camp or perhaps needed a tip so bad; he was so spinlessly and sugary obsequious {'yes sir, no sir, whatever you want or say sir'}); the flunkies that sop up popular opinions without question
obsequiously.adverb
obsequiousness.noun

osteomalacia.noun
a disease occurring mostly in adult women that results from a deficiency in vitamin D or calcium and is characterized by a softening of the bones with accompanying pain and weakness
osteoporosis.noun,.plural-osteoporoses
a disease in which the bones become extremely porous, are subject to fracture and heal slowly, occurring especially in women following menopause and often leading to curvature of the spine from vertebral collapse
osteoporotic.adjective

orgasm.noun,.plural.orgasms
the highest point of sexual excitement, characterized by strong feelings of pleasure and marked normally by ejaculation of semen by the male and by vaginal contractions in the female; also called climax; a point of intensity of emotional excitement
orgasmic or orgastic.adjective
orgasmically or orgastically.adverb

ostensive.adjective
seeming or professed; ostensible
ostensively.adverb
ostensible.adjective
represented or appearing as such; ostensive.(the ostensible purpose was charity, but his real goal was popularity)
ostensibly.adverb

obdurate.adjective
hardened in wrongdoing or wickedness; stubbornly impenitent; hardened against feeling; hardhearted; not giving in to persuasion; intractable; inflexible; if you describe someone as obdurate, you think that they are being unreasonable in their refusal to change their decision or opinion
obdurately.adverb
obdurateness.noun

obsolete.adjective
no longer in use (an obsolete word); old; outmoded in design, style or construction (an obsolete locomotive)
obsolete, obsoleted, obsoleting, obsoletes.transitive verbs-
to cause to become obsolete; to fall into disuse; obsolescent
obsoletely.adverb
obsoleteness, obsoletism.nouns

ooze, oozed, oozing, oozes.verbs
intransitive verb use.to flow or leak out slowly, as through small openings; to disappear or ebb slowly; (his courage oozed away); to progress slowly but steadily; to exude moisture; to emit a particular essence or quality (the house oozed with charm)
transitive verb use.to give off; exude; to emit or radiate in abundance (he oozes confidence)
ooze.noun
the act of oozing; something that oozes
ooze.noun
soft mud or slime; a layer of mudlike sediment on the floor of oceans and lakes, composed chiefly of remains of microscopic sea animals; muddy ground

overshoot, overshot, overshooting, overshoots.verbs
transitive verb use.to shoot or pass over or beyond; to miss by or as if by shooting, hitting or propelling something too far (the batter's hit overshot the outfield); to fly beyond or past; overrun (the plane overshot the runway); to go beyond; exceed
intransitive verb use.to shoot or go too far
overshoot.noun,.plural.overshoots
(practicing landing the plane, he had two overshoots of the runway before landing it properly)

override, overrode, overridden, overriding, overrides.transitive verbs-
to ride across; to ride beyond; to trample on (vaccines override one's innate.immune system, leading sooner or later to serious illness); to ride a horse too hard; to prevail over; conquer; to declare.null and void; set aside (congress overrode the President's veto); to counteract the normal operation of (an automatic control); to extend over
overriding, overridingly.adjective
first in priority; more important than all others (our overriding concern is the eradication of illiteracy); in a particular.situation, the overriding factor is the one that is the most important (her overriding concern is to raise the standards of education)
overlap
override.noun,.plural.overrides
overrider.noun,.plural.overriders

overrule, overruled, overruling, overrules.transitive verbs
to disallow the action or arguments of (the defense attorney's objection was overruled by the judge); to decide or rule against (overrule a policy decision); to declare.null and void; reverse; to rule over (the ancient.Chaldean empire ruled over many countries); to dominate by strong influence; prevail over

overrun, overran, overrunning, overruns.verbs
transitive verb use.to spread or swarm over destructively (locusts overran the prairie); to spread swiftly.throughout (the new fashion overran the country); to overflow (the river overran its banks); to run beyond or past; overshoot (the plane overran the end of the runway); to run or extend beyond a limit set by; exceed (her speech has overrun the time limit); in printing, to rearrange or move set type or pictures from one column, line or page to another; to set too much type for; to print a job order in a quantity larger than that ordered
intransitive verb use.to run over; overflow; to go beyond the normal or desired limit
overrun.noun,.plural.overruns
an act of overrunning; the amount by which something overruns; the exceeding of estimated costs for product development and manufacture covered by contract (on the last job we had higher than expected cost overruns); the amount by which actual costs exceed estimates (they told us the renovation amount, but it turned out having a cost overrun into the thousands of dollars); in printing, a run over and above the quantity ordered by a customer

override.noun,.plural.override
a sales commission collected by an executive in addition to the commission received by a subordinate salesperson; royalty; a mechanism or system used to counteract an automatic control; the act or an instance of nullifying

overlap, overlapped, overlapping, overlaps.verbs
transitive verb use.to have an area or a range in common with; to lie or extend over and cover part of
intransitive verb use.to lie over and partly cover something; to correspond in character or function (their duties overlap)
overlap.noun

overlie, overlay,overlain, overlying, overlies.transitive verbs
to lie over or on

obloquy.noun,.plural.obloquies
abusively detractive language or utterance; calumny; the condition of disgrace suffered as a result of abuse or vilification; ill repute; disgrace

orchestrate, orchestrated, orchestrating, orchestrates.transitive verbs
to arrange or control the elements of, as to achieve a desired overall effect (orchestrated the building of a large boat) orchestrator.noun
Music:.to compose or arrange music for performance by an orchestra
orchestra.noun,.plural.orchestras
Music:.a large group of musicians who play together on various instruments, usually including strings, woodwinds, brass instruments and percussion instruments; the instruments played by such a group; the area in a theater or concert hall where the musicians sit, immediately in front of and below the stage; the front section of seats nearest the stage in a theater; the entire main floor of a theater
orchestral.adjective
orchestrally.adverb

opulence.also.opulency.noun
wealth; affluence; great abundance; profusion
opulent.adjective
possessing or exhibiting great wealth; affluent; characterized by rich abundance; luxuriant
opulently.adverb

oblong.adjective
deviating from a square, circular or spherical form by being elongated in one direction; having the shape of or resembling a rectangle or an ellipse; an oblong leaf
oblong.noun
an object or a figure, such as a rectangle, with an elongated shape

order.noun,.plural.orders
if something must happen in order for something else to happen, the second thing cannot happen if the first thing does not happen (in order for their computers to trace a person's records, they need both the name and address of the individual); a condition of logical or comprehensible arrangement among the separate.elements of a group (the young son had his socks, underwear and sweaters all in order within the chest of drawers; everything at work was in good order and toward safety; the natural order of the universe); a sequence or an arrangement of successive things (such as the digits 1,2,3,4,5 or 5,4,3,2,1 which are numbers respectively in ascending and descending order); a prescribed form or customary.procedure (the order of a 5 course dinner); a command or direction (I gave them an order for items to be delivered today); that which is supplied, bought or sold; a request made by a customer at a restaurant for a portion of food; the food requested; order is also the situation that exists when people obey the law and do not fight or riot
Mathematics:.in mathematics, it means the sum of the exponents to which the variables in a term are raised; degree; an indicated number of successive.differentiations to be performed; the number of elements in a finite group

order.noun,.plural.orders
a group of animals or persons or living under a category or religious rule (a serpent of the order Serpentes; the passerine order of birds; the Order of Saint Benedict; the Order of the Garter; the Order of the Knights Templars); the insignia worn by such people
out of order.idiom

order, ordered, ordering, orders.verbs
transitive verb use.to issue a command or an instruction to; command; to give a command or an instruction for (he ordered a recount of the ballots); to direct to proceed as specified (ordered them off the property); to give an order for; request to be supplied with; to put into a methodical, systematic arrangement; to arrange
intransitive verb use.to give an order or orders; request that something be done or supplied
in order.idiom
if you think something is in order, you think it should happen or be provided (I think a celebration is in order); you use 'in the order of' or 'of the order of' when mentioning an approximate figure (they have something in the order of 2 million); if something is in 'good order', it is in good condition (the vessel's safety equipment was in good order); appropriate, desirable; marked.by.system; organization (everything is now in order in the garage)
in order for.idiom
so that
in order that.idiom
so that
in order to.idiom
for the purpose of; with the purpose of doing
in short order.idiom
with no delay; quickly
on order.idiom
requested but not yet delivered
on the order of.idiom
of a kind or fashion similar to; like (a house on the order of a mountain lodge); approximately; about (equipment costing on the order of a million dollars)
to order.idiom
according to the buyer's specifications
orderer.noun

orderly.adjective
free from disorder; neat (an orderly room); having a systematic arrangement (an orderly universe); marked by or adhering to method or system (orderly in the upkeep of his room); devoid of violence or disruption; peaceful
orderly.noun, plural.orderlies
an attendant who does routine, nonmedical work in a hospital; a soldier assigned to attend a superior officer and perform various tasks
orderly.adverb
systematically; regularly
orderliness.noun