Word origins

• obviationThe act of obviating; deterrence or prevention.
• occasionateTo occasion.
• ochoneExpresses woe or sorrow.
• -ockForming nouns from nouns, originally with a diminutive sense.
• o'clockIn conjunction with a numeral, indicates the time within a twelve-hour period (midnight to noon or noon to midnight), specifically the time when the hour hand of a clock points precisely to the symbol or marking corresponding to the designated numeral, i.e., at the hour.
• octroyTo grant (a privilege etc, by a government etc).
• off-Away from; off.
• offcastTo cast off; shed.
• offcutTo cut off.
• offholdTo retain.
• officialhoodThe state or condition of being official; officiality
• officialshipThe position or role of an official.
• offsmiteTo strike off; cut off.
• offstandTo endure against; stand or ward off; defend against; withstand; resist.
• oftentideOften; frequently.
• oftentime(elsewhere, archaic) Synonym of oftentimes.
• ogiveThe curve of a cumulative distribution function.
• oilishCharacteristic of or resembling oil.
• oil of olivesOlive oil.
• old ageThe latter part of life, when one is an older adult; especially, the years from age 65 onward.
• oldlyIn an old manner.
• old manAn elderly man.
• old moonThe phase of the moon when it is waning.
• oldnessThe state of being old; age.
• old sawA cliché, saying, or overused expression, especially a proverb or maxim.
• Old TestamentReminiscent of the content of the Old Testament, or of the behavior of God in it; especially dramatic, violent or vengeful.
• old wifeAn old woman, later especially one who tells old wives' tales.
• oleasterA plant in the family Elaeagnaceae,
• olifantAn ancient hunting horn, made of ivory.
• oliphauntelephant
• on-on, at, toward, upon.
• onagerThe Asiatic wild ass or hemione (Equus hemionus), an animal of the horse family native to Asia; specifically, the Persian onager, Persian wild ass, or Persian zebra (Equus hemionus onager).
• oncomeTo arrive; come to; come on.
• oncostAdditional costs; extra expenses.
• ondingBreathing; smelling.
• one-eyedHaving only a single eye, particularly when a greater number is normal.
• onefoldConstituting or being indicative of a single aspect or theme.
• one-footedHaving one foot.
• one-handedHaving only one hand.
• oneheadOneness; unity.
• onehoodUnity; agreement.
• one'sBelonging to one.
• onfallA falling on or upon; an attack, onset, or assault.
• on fireBeing burned by fire.
• on footOn one's feet; walking, jogging or running but not in a vehicle or on the back of an animal.
• ongangA start-up; beginning; commencement (of activity, work, machinery, etc.); a setting in motion.
• on handAvailable; ready; in stock.
• on highTo a high position; or up in, or to, the sky; above.
• onlinessThe state of being alone or unique.
• only-begottenBeing the only child of one’s parent (especially one’s father)
• onlyhoodthe condition of being unique, single, or alone
• onsendTo send; send on; send out; forward; transmit.
• ontakeTo take on; undertake; assume.
• open-arseThe medlar fruit.
• open seaThat part of the sea out of sight of land.
• oppilateTo block, to stop up, to obstruct.
• opprobryOpprobrium.
• -orCreates an agent noun, often from a verb, indicating a person or object (often machines or parts of them) that do the verb or part of speech with which they are formed.
• ordalianOf or relating to trial by ordeal.
• ordureDung, excrement.
• orfevrerieThe work or trade of a goldsmith.
• orgueilPride.
• orgulitypride
• orgulousArrogant, haughty, proud.
• orlopThe platform over the hold of a ship that makes up the fourth or lowest deck, hence in full called orlop deck, especially of a warship.
• orpedBold, brave, valiant; active, alert; self-assured, hardy, vigorous.
• orpedlyBoldly; bravely; stoutly.
• orphreyAny elaborate embroidery, especially when made of gold thread; an object (such as clothing or fabric) adorned with such embroidery.
• orpimentArsenic trisulphide, occurring naturally in crystals or massive deposits, formerly used as a dye or pigment.
• -oryAdded to nouns and verbs (often Latinate) to form adjectives meaning “of”, “pertaining to”, or “serving for”.
• otherlyPertaining to something or someone else; different.
• othersomeSome others.
• otherwardToward an other.
• oucheA brooch or clasp for fastening a piece of clothing together, especially when set with jewels or valuable.
• -ourUsed to form abstract nouns of state, quality, or action from Latin or French roots.
• Our LadySynonym of Mary, mother of Jesus, particularly in Catholic contexts.
• ournOurs.
• -ouspossession of
• out-External to, on the outside of
• outbearTo bear out; support.
• outblowTo blow out (all senses)
• outbreakingThe act of breaking out; an outbreak.
• outbringTo bring out; deliver; utter; express.
• outbyeIn the direction away from the coal face.
• outcomelingA stranger; foreigner.
• outcomingThat comes out.
• outcreepTo creep or crawl out.
• outdrinkTo drink more than (someone else).
• outfangthiefA privilege of some feudal lords permitting them to execute summary judgment upon thieves (particularly their own tenants) captured outside their estates and to keep any chattels forfeited upon conviction.
• outgangAn exit or egress.
• outgoerOne who or that which goes out or departs.
• outhaulTo haul out.
• outholdTo hold out; extend.
• outlawryA declaration that an individual cannot benefit from the protection of law in a jurisdiction.
• outleadTo lead out.
• out ofFrom the inside to the outside of.
• outscrapeTo escape
• outseekTo seek out; actively or diligently search for; investigate; research.
• outsendTo send out or forth; issue; emit; transmit; broadcast.
• outshoveTo shove harder or better than; outcompete by shoving