O — oa ob oc od oe of og oh oi ok ol om on oo op or os ot ou ov ow ox oy oz
op |ɑːp| — (law) Abbreviation of opinion.
op-ed |ˈɑpˌed| — simple past tense and past participle of ope
opacity |əʊˈpæsətɪ| — the phenomenon of not permitting the passage of electromagnetic radiation
opal |ˈəʊpl| — a translucent mineral consisting of hydrated silica of variable color; some varieties are used as gemstones
opalescent |ˌəʊpəˈlesnt| — having a play of lustrous rainbow colors
opaline |ˈəʊp(ə)liːn| — having a play of lustrous rainbow colors
opaque |əʊˈpeɪk| — hard or impossible to understand
opaqueness |əʊˈpeɪknəs| — incomprehensibility resulting from obscurity of meaning
ope |əʊp| — (now dialectal or poetic) Open. [from 13th c.]
open |ˈəʊpən| — a clear or unobstructed space or expanse of land or water
open up |ˈəʊpən ʌp| — cause to open or to become open
open-air |ˈəʊpənər| — in the open air
open-and-shut |ˈəʊpənər| — so obvious as to be easily solved or decided
open-ended |ˌəʊpən ˈendɪd| — without fixed limits or restrictions
open-eyed |ˌəʊpən ˈaɪd| — carefully observant or attentive; on the lookout for possible danger
open-faced |ˈəʊpnˈfeɪst| — (of a sandwich) Being a single slice of bread with a topping
open-handed |ˌəʊpən ˈhændɪd| — Generous; giving freely.
open-hearted |ˌəʊpən ˈhɑːrtɪd| — frank and candidly straightforward
open-minded |əʊpən ˈmaɪndɪd| — ready to entertain new ideas
open-mindedness — Alternative form of open-mindedness.
open-mouthed |ˌəʊpən ˈmaʊðd| — Alternative form of open-mouthed.
open-source |əʊp(ə)nˈsɔːs| — of or relating to or being computer software for which the source code is freely available
open-work |ˈəʊpənwɜːk| — Alternative spelling of openwork.
opencast |ˈəʊpənkæst| — (of mines and mining) worked from the exposed surface
opened |ˈəʊpənd| — made open or clear
opener |ˈəʊpnər| — the first event in a series
opening |ˈəʊpnɪŋ| — an open or empty space in or between things
openly |ˈəʊpənlɪ| — in an open way
openness |ˈəʊpənnəs| — without obstructions to passage or view
openwork |ˈəʊpənwɜːk| — ornamental work (such as embroidery or latticework) having a pattern of openings
opera |ˈɑːprə| — a drama set to music; consists of singing with orchestral accompaniment and an orchestral overture and interludes
opera-glass |ˈɒpərəˌɡlɑːs| — A pair of small low-powered binoculars for use at a theatrical performance.
opera-glasses |ˈɒpərə ɡlæsɪz| — plural form of opera glass
opera-hat |ˈɒpərə hæt| — A kind of collapsible top hat.
opera-house |ˈɒpərə haʊs| — A theatre, or similar building, primarily used for staging opera.
operable |ˈɑːpərəbl| — fit or ready for use or service
operand |ˈɑːpərænd| — a quantity upon which a mathematical operation is performed
operant |ˈɑːpərənt| — having influence or producing an effect
operate |ˈɑːpəreɪt| — direct or control; projects, businesses, etc.
operated |ˈɑːpəˌretəd| — simple past tense and past participle of operate
operatic |ˌɑːpəˈrætɪk| — of or relating to or characteristic of opera
operating |ˈɑːpəˌretɪŋ| — being in effect or operation
operating-room |ˈɒpəreɪtɪŋrʊm| — a room in a hospital used for performing surgery
operating-theatre |ˈɒpəreɪtɪŋ θɪətər| — attributive form of operating theatre
operation |ˌɑːpəˈreɪʃn| — the state of being in effect or being operative
operational |ˌɑːpəˈreɪʃənl| — fit or ready for use or service
operationalize |ɒpəˈreɪʃ(ə)n(ə)laɪz| — To make operational.
operationally |ˌɑːpəˈreɪʃənlɪ| — in respect to operation
operative |ˈɑːpərətɪv| — a person secretly employed in espionage for a government
operator |ˈɑːpəreɪtər| — (mathematics) a symbol or function representing a mathematical operation
operetta |ˌɑːpəˈretə| — a short amusing opera
operose |ˈɒpərəʊs| — characterized by effort to the point of exhaustion; especially physical effort
ophidian |əʊˈfɪdiːən| — limbless scaly elongate reptile; some are venomous
ophiolatry |ɑːfiːˈɑːlətriː| — the worship of snakes
ophite |ˈɑːfaɪt| — (geology) Any of various rocks having snake-like markings, such as a mottled greenish porphyry. [from 16th c.]
ophthalmia |ɒfˈθælmɪə| — severe conjunctivitis
ophthalmic |ɑːfθælmɪk| — of or relating to ophthalmology
ophthalmologist |ˌɑːfθælˈmɑːlədʒɪst| — a medical doctor specializing in the diagnosis and treatment of diseases of the eye
ophthalmology |ˌɑːfθælˈmɑːlədʒɪ| — the branch of medicine concerned with the eye and its diseases
opiate |ˈəʊpɪət| — a narcotic drug that contains opium or an opium derivative
opine |əʊˈpaɪn| — express one's opinion openly and without fear or hesitation
opinion |əˈpɪnjən| — a personal belief or judgment that is not founded on proof or certainty
opinionated |əˈpɪnjəneɪtɪd| — obstinate in your opinions
opioid |ˈəʊpɪɔɪd| — A substance that is like opium.
opium |ˈəʊpɪəm| — an addictive narcotic extracted from seed capsules of the opium poppy
opodeldoc |ˌɑːpəˈdeldɑːk| — (obsolete) A kind of plaster, said to have been invented by Mindererus, used for external injuries.
opossum |əˈpɑːsəm| — small furry Australian arboreal marsupials having long usually prehensile tails
oppidan |ˈɑːpɪdən| — (rare) Of or pertaining to a town or conurbation.
oppo |ˈɒpəʊ| — (UK, informal) A friend, associate or colleague.
opponent |əˈpəʊnənt| — a contestant that you are matched against
opportune |ˌɑːpərˈtuːn| — suitable or at a time that is suitable or advantageous especially for a particular purpose
opportunely |ˈɒpətjuːnlɪ| — at an opportune time
opportuneness — timely convenience
opportunism |ˌɑːpərˈtuːnɪzəm| — taking advantage of opportunities without regard for the consequences for others
opportunist |ˌɑːpərˈtuːnɪst| — a person who places expediency above principle
opportunistic |ˌɑːpərtuːˈnɪstɪk| — taking immediate advantage, often unethically, of any circumstance of possible benefit
opportunity |ˌɑːpərˈtuːnətɪ| — a possibility due to a favorable combination of circumstances
oppose |əˈpəʊz| — be against; express opposition to
opposed |əˈpəʊzd| — being in opposition or having an opponent
opposer — someone who offers opposition
opposing |əˈpəʊzɪŋ| — characterized by active hostility
opposite |ˈɑːpəzət| — a word that expresses a meaning opposed to the meaning of another word, in which case the two words are antonyms of each other
opposition |ˌɑːpəˈzɪʃn| — the action of opposing something that you disapprove or disagree with
oppositional |ˌɑːpəˈzɪʃənl| — Of, pertaining to, or exhibiting opposition
oppositionist |ˌɒpəˈzɪʃənɪst| — A person who opposes; especially a member of an official opposition
oppress |əˈpres| — come down on or keep down by unjust use of one's authority
oppressed |əˈprest| — burdened psychologically or mentally
oppressing |əˈpresɪŋ| — Present participle of oppress.
oppression |əˈpreʃn| — the act of subjugating by cruelty
oppressive |əˈpresɪv| — weighing heavily on the senses or spirit
oppressiveness |əˈpresɪvnɪs| — a feeling of being oppressed
oppressor |əˈpresər| — a person of authority who subjects others to undue pressures
opprobrious |əˈprəʊbrɪəs| — expressing offensive reproach
opprobrium |əˈprəʊbrɪəm| — state of disgrace resulting from public abuse
oppugn |əˈpjuːn| — challenge the accuracy, probity, or propriety of
oppugnant |əˈpəɡnənt| — opposing, antagonistic, contrary
opt |ɑːpt| — select as an alternative over another
opt out |ˈɑːpt ˈaʊt| — choose not to do something, as out of fear of failing
optative |ˈɒptətɪv| — a mood (as in Greek or Sanskrit) that expresses a wish or hope; expressed in English by modal verbs
opted |ˈɑːptəd| — simple past tense and past participle of opt
optic |ˈɑːptɪk| — the organ of sight
optical |ˈɑːptɪkl| — of or relating to or involving light or optics
optically |ˈɑːptɪkəlɪ| — in an optical manner
optician |ɑːpˈtɪʃn| — a worker who makes glasses for remedying defects of vision
optics |ˈɑːptɪks| — the branch of physics that studies the physical properties of light
optimal |ˈɑːptɪməl| — most desirable possible under a restriction expressed or implied
optimally |ˈɑːptɪməlɪ| — in an optimal and most desirable way
optimism |ˈɑːptɪmɪzəm| — the optimistic feeling that all is going to turn out well
optimist |ˈɑːptɪmɪst| — a person disposed to take a favorable view of things
optimistic |ˌɑːptɪˈmɪstɪk| — expecting the best
optimistical |ˌɒptɪˈmɪstɪkəl| — optimistic
optimization |aptəməˈzeɪʃən| — the act of rendering optimal
optimize |ˈɑːptɪmaɪz| — make optimal; get the most out of; use best
optimum |ˈɑːptɪməm| — most favorable conditions or greatest degree or amount possible under given circumstances
option |ˈɑːpʃn| — the right to buy or sell property at an agreed price; the right is purchased and if it is not exercised by a stated date the money is forfeited
optional |ˈɑːpʃənl| — possible but not necessary; left to personal choice
optometrist |ɑːpˈtɑːmətrɪst| — a person skilled in testing for defects of vision in order to prescribe corrective glasses
optophone |ˈɑːptəfəʊn| — A device that transforms light into sound.
opulence |ˈɑːpjələns| — wealth as evidenced by sumptuous living
opulent |ˈɑːpjələnt| — ostentatiously rich and superior in quality
opus |ˈəʊpəs| — a musical work that has been created
opuscule |əʊˈpʌskjuːl| — A small or petty work.