osseous
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C2 adjective /ˈɒsiəs/

osseous

óseo
Meaning
consisting of or turned into bone; bony
Example
The fossil showed osseous structures of the ancient creature.
El fósil mostró estructuras óseas de la antigua criatura.
B2 verb /ˌoʊvərˈiːt/

overeat

felicidad
Meaning
To eat more food than the body needs.
Example
She tends to overeat when she is stressed.
Ella no pudo ocultar su felicidad cuando recibió el premio.
C1 verb /uːz/

ooze

filtrarse
Meaning
to slowly flow or leak out through small openings or pores
Example
Blood began to ooze from the small cut.
La sangre comenzó a filtrarse de la pequeña herida.
C1 adjective /əbˈstrʌk.tɪv/

Obstructive

obstructivo
Meaning
deliberately creating difficulties or preventing progress; hindering or blocking something
Example
The obstructive policies hindered economic growth.
Las políticas obstructivas obstaculizaron el crecimiento económico.
C2 noun /ˈɔːrdʒi/

orgy

fiesta desmedida
Meaning
A wild party involving excessive indulgence, especially of a sexual nature.
Example
The novel described a scandalous orgy in a wealthy mansion.
La novela describió una orgía escandalosa en una mansión rica.
C2 adjective /ˈɑːbdjʊrət/

obdurate

obstinado
Meaning
Stubbornly refusing to change one's opinion or course of action.
Example
He remained obdurate despite everyone's pleas.
Él permaneció obstinado a pesar de las súplicas de todos.
C2 noun /ˈoʊpiət/

opiate

opiáceo
Meaning
a drug containing opium or its derivatives, used to relieve pain or cause sleep
Example
The doctor prescribed an opiate to relieve the patient's pain.
El médico recetó un opiáceo para aliviar el dolor del paciente.
B2 verb /əˈpoʊz/

oppose

oponerse
Meaning
to disagree with or resist; to act against
Example
Many citizens oppose the new tax policy.
Muchos ciudadanos se oponen a la nueva política fiscal.
B2 noun /ˈɔːrɡənaɪzər/

organizer

organizador
Meaning
a person who arranges or coordinates activities, events, or groups; a tool or item used to keep things in order
Example
She worked as the main organizer of the international conference.
Ella fue la principal organizadora de la conferencia internacional.
B1 verb /ˈɒpəreɪtɪŋ/

operating

operando
Meaning
to control or manage the functioning of something
Example
The company has been operating in this market for five years.
La compañía ha estado operando en este mercado durante cinco años.
A2 adjective /ˈɔː.dɪ.nər.i/

Ordinary

ordinario; común; no especial
Meaning
normal; usual; not special
Example
It was just an ordinary day at the office.
Era solo un día ordinario en la oficina.
C2 noun /ˈɔːrɪndʒfɪn ˈleɪbiːoʊ/

Orangefin labeo

labeo de aleta naranja
Meaning
a freshwater fish species native to South Asian rivers, commonly found in Bangladesh and India
Example
The orangefin labeo is an important food fish in Bangladesh.
El labeo de aleta naranja es un pez alimenticio importante en Bangladesh.
B1 adjective /əˈrɪdʒ.ɪ.nəl/

Original

original; primario; auténtico
Meaning
first; fundamental; primary; authentic
Example
This is the original document, not a copy.
Este es el documento original, no una copia.
C2 noun /ˌoʊpəˈlɛsəns/

opalescence

opalescencia
Meaning
a milky or pearly appearance of a surface like that of an opal
Example
The pearl had a gentle opalescence under the light.
La perla tenía una suave opalescencia bajo la luz.
B1 verb /ˈɔːrɡənaɪz/

organize

organizar
Meaning
to arrange systematically; to plan and coordinate
Example
She organized a surprise party for her friend.
Ella organizó una fiesta sorpresa para su amiga.
B2 adverb /ˈaʊtraɪt/

Outright

directamente; completamente; sin reservas
Meaning
completely; directly; without reservation or concealment
Example
She rejected the proposal outright.
Ella rechazó la propuesta directamente.
C1 noun /oʊˈbɪt.ʃu.er.i/

Obituary

obituario
Meaning
a notice of someone's death published in a newspaper; biographical account of deceased person
Example
The newspaper published his obituary yesterday.
El periódico publicó su obituario ayer.
C1 verb /ɔːrˈdeɪn/

ordain

ordenar
Meaning
To officially make someone a priest or minister; to decree or order something officially.
Example
The bishop will ordain three new priests this Sunday.
El obispo ordenará tres nuevos sacerdotes este domingo.
B1 adjective /əˈfɪʃəl/

official

oficial
Meaning
relating to or connected with an authority or public office
Example
He is the official spokesperson for the company.
Él es el portavoz oficial de la empresa.
C2 noun /ˈɒn.rʌʃ/

onrush

embestida
Meaning
A sudden powerful forward or downward rush or flow.
Example
The onrush of water swept away the bridge.
La embestida de agua arrastró el puente.
C2 noun /ˈɒksɪdənt/

occident

occidente
Meaning
The countries of the West, especially Europe and America.
Example
The Occident has a long history of philosophical thought.
El occidente tiene una larga historia de pensamiento filosófico.
C1 verb /ˌoʊvərˈrʌn/

overrun

invadir
Meaning
to spread over or occupy completely; to exceed a limit or time
Example
The garden was overrun with weeds.
El jardín estaba invadido de maleza.
C1 noun /ˈaʊtriːtʃ/

outreach

expansión de la asistencia
Meaning
The act of providing services or support to people who might not otherwise have access to them.
Example
The charity launched a new outreach program for the homeless.
La caridad lanzó un nuevo programa de expansión de la asistencia para las personas sin hogar.
C1 adjective ˈɒk.sɪ.də.tɪv

oxidative

Relacionado con la oxidación
Meaning
Related to or caused by oxidation, especially cellular damage from free radicals.
Example
Excess stress can lead to oxidative damage in cells.
El estrés excesivo puede causar daño oxidativo en las células.
A1 adjective /əʊˈkeɪ/

okay

está bien
Meaning
used to express agreement or acceptance
Example
It's okay to leave early today.
Está bien irse temprano hoy.
C1 adjective /ˌɒmnɪˈprezənt/

omnipresent

omnipresente
Meaning
(of God) present everywhere at the same time.
Example
Social media has become an omnipresent force in modern society.
Las redes sociales se han convertido en una fuerza omnipresente en la sociedad moderna.
C1 noun /ˈɑn.set/

Onset

inicio; comienzo
Meaning
the beginning or early stages of something; the start of a medical condition
Example
The onset of winter brought heavy snowfall.
El inicio del invierno trajo fuertes nevadas.
C1 verb /aʊtˈlɪv/

outlive

sobrevivir
Meaning
to live longer than someone or something else
Example
She outlived all her siblings.
Ella vivió más tiempo que todos sus hermanos.
B2 noun /ˈɔːkɪstrə/

orchestra

orquesta
Meaning
a large group of musicians playing different instruments together
Example
The orchestra performed beautifully at the concert.
La orquesta actuó maravillosamente en el concierto.
B1 noun /ˈɔr.ə.ʒɪn/

Origin

origen
Meaning
the point or place where something begins, arises, or is derived; the source
Example
Scientists are studying the origin of the universe.
Los científicos están estudiando el origen del universo.
C2 noun /ˈoʊ.kəm/

oakum

fibra de cuerda vieja
Meaning
loose fibers obtained by untwisting old ropes, used for caulking ships
Example
The shipbuilders used oakum to seal the gaps in the wooden planks.
Los constructores de barcos usaron oakum para sellar las grietas en las tablas de madera.
C2 noun ˈɒpjʊləns

opulence

opulencia
Meaning
Great wealth or luxuriousness.
Example
The opulence of the mansion was evident in its ornate furnishings.
La opulencia de la mansión era evidente en sus muebles ornamentados.
C1 adjective /ˌɔː.riˈen.təl/

Oriental

relativo a los países del Este de Asia; oriental
Meaning
relating to the countries of East Asia; eastern
Example
The museum has a beautiful collection of oriental art.
El museo tiene una hermosa colección de arte oriental.
B2 adjective /ˌɑːp.təˈmɪs.tɪk/

optimistic

optimista
Meaning
hopeful and confident about the future
Example
She is optimistic about the success of her new project.
Ella está optimista acerca del éxito de su nuevo proyecto.
C2 noun /əbˈsɪdiən/

obsidian

obsidiana (roca volcánica oscura y vidriosa)
Meaning
A hard, dark, glasslike volcanic rock formed by rapid solidification of lava.
Example
The knife was made from sharp obsidian.
El cuchillo estaba hecho de obsidiana afilada.
C1 noun /əbˈstrʌkʃən/

obstruction

obstáculo
Meaning
Something that blocks or gets in the way; the action of obstructing.
Example
There was an obstruction on the railway track.
Había un obstáculo en la vía del tren.
B2 noun /ˈaʊt.kʌm/

Outcome

resultado; consecuencia;
Meaning
the result or consequence of an action or situation; the final product
Example
The outcome of the election surprised everyone.
El resultado de las elecciones sorprendió a todos.
C2 adjective /ˈɔːrəˌtʌnd/

orotund

voz grave y clara
Meaning
full, rich, and clear in sound; pompous in style
Example
The actor's orotund voice filled the theater.
La voz grave del actor llenó el teatro.
C1 noun /ˈaʊtˌɡroʊθ/

outgrowth

desarrollo
Meaning
something that grows out of something else; a natural development or result
Example
The new policy was an outgrowth of years of debate.
La nueva política fue un desarrollo de años de debate.
C2 noun /ˈɔː.rɪ.fɪs/

orifice

orificio
Meaning
an opening or hole, especially in the body or a device
Example
The medicine was applied through a small orifice in the device.
El medicamento se aplicó a través de un pequeño orificio en el dispositivo.
C1 adjective /ˌaʊt əv ðə ˈweɪ/

out-of-the-way

apartado o remoto
Meaning
remote or unusual; not in a convenient or usual location
Example
They stayed in an out-of-the-way village.
Se quedaron en una aldea apartada.
C2 verb /oʊˈpaɪn/

opine

expresar una opinión
Meaning
to express an opinion or belief
Example
The professor opined that the policy would fail.
El profesor opinó que la política fracasaría.
B2 verb /əbˈteɪn/

obtain

obtener
Meaning
to get or acquire something
Example
You need to obtain a visa before traveling abroad.
Necesitas obtener una visa antes de viajar al extranjero.
C2 adjective /ˌoʊpəˈlɛsənt/

opalescent

opalescente
Meaning
showing or reflecting a milky, iridescent light like an opal
Example
The opalescent sky glowed with shades of pink and blue.
El cielo opalescente brillaba con tonos de rosa y azul.
B2 verb /ɒpt/

opt

elegir
Meaning
to choose or decide to do something instead of something else
Example
Many students opt to study abroad for better opportunities.
Muchos estudiantes optan por estudiar en el extranjero para tener mejores oportunidades.
C1 noun /ˈɔr.ə.tər/

Orator

orador
Meaning
a public speaker, especially one who is eloquent or skilled in speaking
Example
The famous orator delivered an inspiring speech.
El famoso orador pronunció un discurso inspirador.
A1 adjective /oʊld/

old

viejo
Meaning
having lived for a long time; not new or young
Example
He still drives his old car.
Él todavía conduce su coche viejo.
B2 noun /ˈɔːɡən/

organ

órgano
Meaning
a part of the body that performs a specific function
Example
The heart is an important organ in the human body.
El corazón es un órgano importante en el cuerpo humano.
B2 noun /ɑːks/

Ox

buey
Meaning
a large strong animal used for pulling heavy loads or plowing fields
Example
The farmer used an ox to plow the field.
El agricultor usó un buey para arar el campo.
C1 noun /ˈɑːdəsi/

odyssey

viaje largo
Meaning
a long, adventurous journey; a series of experiences
Example
Her career has been an odyssey of challenges and achievements.
Su carrera ha sido una odisea de desafíos y logros.
C1 noun /oʊθ/

Oath

juramento
Meaning
a solemn promise or declaration; a sworn statement
Example
The doctor took an oath to help patients.
El doctor hizo un juramento de ayudar a los pacientes.
C1 noun /ˈɑːlɪˌɡɑːrki/

oligarchy

oligarquía
Meaning
A small group of people having control of a country, organization, or institution.
Example
The nation was ruled by a wealthy oligarchy that controlled all resources.
La nación fue gobernada por una oligarquía rica que controlaba todos los recursos.
C2 adjective /ˈoʊ.pən ˈhɑrt.ɪd/

Open-hearted

de corazón abierto; generoso y sincero; cálidamente receptivo;
Meaning
Kind and generous; sincere and honest; warmly receptive;
Example
She welcomed the strangers with an open-hearted smile and invited them for dinner.
Ella dio la bienvenida a los extraños con una sonrisa de corazón abierto e invitó a cenar.
B2 noun /ˈɒt.ər/

Otter

nutria
Meaning
a mammal with webbed feet that lives near water and feeds on fish
Example
The playful otter swam gracefully in the river.
La nutria juguetona nadaba con gracia en el río.
C1 noun /ˈɒf.sprɪŋ/

offspring

descendencia
Meaning
a person's child or children; an animal's young
Example
The bird carefully fed its offspring.
El pájaro alimentó cuidadosamente a su descendencia.
C1 noun ɔːrˈdiːl

ordeal

prueba difícil
Meaning
A physical or mental painful experience that must be endured
Example
Surviving the wilderness was a tough ordeal for them.
Sobrevivir en la naturaleza fue una dura prueba para ellos.
C2 noun /ˌɔːrnɪˈθɒlədʒɪst/

ornithologist

ornitólogo
Meaning
a scientist who studies birds
Example
The ornithologist spent years studying migratory birds.
El ornitólogo pasó años estudiando aves migratorias.
C2 noun /ɔːˈreɪʃən/

oration

discurso
Meaning
A formal speech, especially one given on a ceremonial occasion
Example
The president delivered an inspiring oration.
El presidente dio un discurso inspirador.
B2 adjective /ˈɔɪl.i/

Oily

oleoso; cubierto de aceite; grasoso
Meaning
covered with oil; containing oil; greasy
Example
Her oily skin needs special care.
Su piel aceitosa necesita cuidados especiales.
B2 adjective /ˈɔː.rəl/

Oral

oral; relacionado con la boca
Meaning
spoken rather than written; relating to the mouth
Example
The oral examination will test your speaking skills.
El examen oral evaluará tus habilidades de hablar.
C1 verb /ˌoʊvərˈθroʊ/

overthrow

felicidad
Meaning
To remove a leader or government from power, often by force.
Example
The rebels planned to overthrow the corrupt regime.
No pudo esconder su felicidad cuando recibió el premio.
B2 noun /ˈoʊ.dər/

Odour

olor
Meaning
a distinctive smell, especially an unpleasant one
Example
The odour of fresh bread filled the kitchen.
El olor de pan fresco llenó la cocina.
C1 noun /əbˈzɜːrvətɔːri/

observatory

observatorio
Meaning
A building equipped for observing astronomical or meteorological events.
Example
The observatory is open to the public on weekends.
El observatorio está abierto al público los fines de semana.
A2 verb /ˈɔːfər/

offer

ofrecer
Meaning
to present something for acceptance or rejection; to propose
Example
She offered to help with the project.
Ella se ofreció a ayudar con el proyecto.
C1 noun /ɒpˈtɒmətri/

optometry

optometría
Meaning
The practice or profession of examining the eyes and prescribing corrective lenses.
Example
She studied optometry at the university to become an eye specialist.
Estudió optometría en la universidad para convertirse en especialista en ojos.
B1 noun ˌɔː.ɡən.aɪˈzeɪ.ʃən

organization

organización
Meaning
An organized group of people with a particular purpose, such as a business or government department.
Example
The organization was officially inaugurated in 2024.
La organización fue inaugurada oficialmente en 2024.
C1 noun /ˈɒn.slɔːt/

onslaught

asalto
Meaning
A fierce or destructive attack.
Example
The village faced an onslaught of enemy forces.
El pueblo enfrentó un asalto de las fuerzas enemigas.
A1 preposition /ʌv/

of

de
Meaning
expressing the relationship between a part and a whole
Example
The book is on the table, in front of the window.
El libro está sobre la mesa, frente a la ventana.
C2 noun /ˌɔːrəˈtɔːri.oʊ/

oratorio

composición musical religiosa
Meaning
A large-scale musical composition for orchestra, choir, and soloists, usually on a sacred theme, performed without costumes or scenery.
Example
Handel's 'Messiah' is one of the most famous oratorios ever written.
El 'Mesías' de Handel es uno de los oratorios más famosos jamás escritos.
C1 verb əˈblɪt.ə.reɪt

obliterate

destruir
Meaning
To destroy utterly; wipe out completely, to erase or remove something completely.
Example
The storm obliterated entire villages.
La tormenta destruyó aldeas enteras.
C1 noun /ˈɒktɪv/

octave

octava
Meaning
A series of eight musical notes, or the interval between one musical pitch and another with double its frequency.
Example
The singer's voice could easily reach the higher octave.
La voz del cantante podría alcanzar fácilmente la octava más alta.
B1 noun /ˌɑk.jəˈpeɪ.ʃən/

Occupation

ocupación; profesión; toma de control
Meaning
a job or profession; the action of taking control of a place
Example
Teaching is her chosen occupation.
La enseñanza es su ocupación elegida.
C2 noun /ˈɒlɪv bɑːb/

Olive barb

barbo oliva
Meaning
A small freshwater fish with olive-colored body and barbels
Example
The olive barb is commonly found in South Asian rivers.
El barbo oliva se encuentra comúnmente en los ríos del sur de Asia.
C1 adjective /ˌoʊvərˈbɛrɪŋ/

overbearing

opresivo
Meaning
unpleasantly or arrogantly domineering
Example
His overbearing attitude made everyone uncomfortable.
Su actitud opresiva hizo que todos se sintieran incómodos.
C2 noun /ˌɔːrdɪˈneɪʃən/

ordination

ordenación
Meaning
The ceremony of conferring holy orders or official religious authority.
Example
The church held a special service for the ordination of new priests.
La iglesia celebró un servicio especial para la ordenación de nuevos sacerdotes.
C1 noun /əbˈzɜːvəns/

observance

observancia
Meaning
The practice of following a custom, rule, or religious law.
Example
The festival is held in observance of a centuries-old tradition.
El festival se celebra en observancia de una tradición centenaria.
C2 noun ˌɒbfəsˈkeɪʃən

obfuscation

ofuscación, confusión
Meaning
The action of making something obscure, unclear, or unintelligible.
Example
The obfuscation of the data made it difficult to interpret.
La ofuscación de los datos dificultó su interpretación.
B2 adjective; verb (past participle) /ˈɒkjʊpaɪd/

occupied

ocupado
Meaning
being in use or taken; filled or lived in; controlled or held by force
Example
The room is occupied, so please wait outside.
La habitación está ocupada, por favor espere afuera.
B2 adjective /ˈɔː.də.li/

Orderly

ordenado; sistemático; pacífico
Meaning
well-organized; systematic; peaceful
Example
Please keep your desk orderly and clean.
Por favor, mantén tu escritorio ordenado y limpio.
B2 verb /ˌoʊvərˈwɛlm/

overwhelm

abrumar
Meaning
to overpower someone emotionally or physically; to be too much to handle
Example
She was overwhelmed with gratitude after receiving the help.
Ella estaba abrumada de gratitud después de recibir la ayuda.
A2 noun əˈlɪm.pɪk ɡeɪmz

Olympic Games

juegos olímpicos
Meaning
The world's largest international sports competition held every four years, bringing together athletes from different countries to compete in various sports.
Example
The Olympic Games bring together the world's top athletes.
Los Juegos Olímpicos reúnen a los mejores atletas del mundo.
C2 noun /ɒkˈteɪvoʊ/

octavo

octavo (tamaño de libro resultante de doblar una hoja en ocho partes)
Meaning
A size of book page resulting from folding a sheet of paper into eight leaves (sixteen pages).
Example
The old library contained rare octavo editions of Shakespeare.
La antigua biblioteca contenía ediciones raras de octavo de Shakespeare.
C2 noun /ˌɒstɛnˈteɪʃən/

ostentation

ostentación
Meaning
excessive display of wealth or knowledge intended to attract admiration or envy
Example
The billionaire’s party was full of ostentation and luxury.
La fiesta del multimillonario estaba llena de ostentación y lujo.
B2 noun /ˈɑp.tə.mɪst/

Optimist

optimista
Meaning
a person who tends to be hopeful and confident about the future; someone who sees the good side of things
Example
As an optimist, she always believed things would improve.
Como optimista, siempre creyó que las cosas mejorarían.
C1 noun /ˈɒktəɡən/

octagon

octágono
Meaning
A polygon with eight sides and eight angles.
Example
The stop sign is shaped like an octagon.
La señal de alto tiene forma de octágono.
C1 adjective /ˌɑːpərˈtuːn/

opportune

momento oportuno
Meaning
Happening at a suitable or convenient time.
Example
She arrived at an opportune moment to help.
Llegó en un momento oportuno para ayudar.
B2 verb əbˈzɜːrvd

observed

celebrar
Meaning
To celebrate or keep a religious or other festival.
Example
The day is observed annually to raise awareness.
El día se celebra anualmente para aumentar la conciencia.
C1 adjective /əbˈsɛsɪv/

obsessive

obsesivo
Meaning
Relating to or characterized by an obsession; thinking about something too much.
Example
He has an obsessive interest in cleanliness.
Él tiene un interés obsesivo en la limpieza.
A2 noun /ˈoʊpənɪŋ/

opening

apertura
Meaning
an act or instance of beginning something
Example
The opening of the new store was a huge success.
La apertura de la nueva tienda fue un gran éxito.
C2 noun /ˌɑːbdʒərˈɡeɪʃən/

objurgation

reprensión severa
Meaning
a harsh scolding or strong rebuke
Example
His misconduct earned him a severe objurgation from the manager.
Su mala conducta le valió una severa reprensión por parte del gerente.
C2 verb /ˌoʊvərˈstraɪd/

overstride

cruzar dando pasos largos
Meaning
To stride over something; to step across with long steps.
Example
He managed to overstride the narrow stream with ease.
Él logró cruzar el estrecho arroyo con facilidad.
A1 adverb /ˈɔːfən/

often

a menudo
Meaning
frequently, many times
Example
I often visit my grandparents on weekends.
A menudo visito a mis abuelos los fines de semana.
C1 noun /ˈoʊ.mən/

Omen

presagio de buena o mala suerte futura
Meaning
an event regarded as a sign of future good or bad luck
Example
Many people consider a black cat crossing your path a bad omen.
Muchas personas consideran que un gato negro cruzando tu camino es un mal presagio.
B2 noun /ˈaʊtˌsɛt/

outset

comienzo
Meaning
the beginning or start of something
Example
From the outset, the project seemed ambitious but achievable.
Desde el comienzo, el proyecto parecía ambicioso pero alcanzable.
C1 noun /əˈfen.dər/

Offender

delincuente; infractor de la ley
Meaning
a person who commits an illegal act; someone who breaks the law
Example
The young offender was sentenced to community service.
El joven delincuente fue sentenciado a servicio comunitario.
B1 adverb /ˈʌðərwaɪz/

Otherwise

de otra manera; si no; o sino
Meaning
in a different way; if not; or else; apart from that
Example
Study hard, otherwise you will fail the exam.
Estudia mucho, de lo contrario, reprobarás el examen.
B2 adjective /ˈaʊtˌɡoʊɪŋ/

outgoing

sociable
Meaning
Friendly and sociable; inclined to mix with others.
Example
He is an outgoing person who loves meeting new people.
Es una persona sociable a la que le encanta conocer gente nueva.
C1 verb /əˈfɪʃieɪt/

officiate

oficiar
Meaning
To perform official duties, especially in a ceremony or as a referee.
Example
The priest will officiate the wedding ceremony.
El sacerdote oficiará la ceremonia de la boda.
C1 adjective /ˌaʊtˈspoʊkən/

Outspoken

franco
Meaning
frank; speaking directly
Example
She is known for being outspoken about social issues.
Es conocida por ser franca sobre los problemas sociales.
A2 pronoun /aʊərˈsɛlvz/

ourselves

nosotros mismos
Meaning
used by the speaker to refer to themselves and one or more others as the object of the verb
Example
We should help ourselves before helping others.
Debemos ayudarnos a nosotros mismos antes de ayudar a los demás.
C1 noun /əˈpreʃ.ən/

Oppression

opresión; abuso; tiranía;
Meaning
cruel or unjust treatment or exercise of authority; the state of being subject to harsh treatment
Example
The people fought against political oppression.
La gente luchó contra la opresión política.
C2 noun /ˈɑːbəlɪsk/

obelisk

obelisco
Meaning
A tall, four-sided, narrow tapering monument with a pyramid-shaped top.
Example
The ancient Egyptians built obelisks to honor their gods.
Los antiguos egipcios construyeron obeliscos para honrar a sus dioses.
B1 adjective /əˈkeɪ.ʒən.əl/

Occasional

ocasional
Meaning
occurring infrequently or irregularly; happening from time to time
Example
She enjoys occasional walks in the park.
Ella disfruta de paseos ocasionales en el parque.
C1 noun əˈblɪv.i.ən

oblivion

olvido, destrucción, desaparición
Meaning
The state of being unaware or unconscious of what is happening; complete forgetfulness.
Example
His name faded into oblivion over time.
Su nombre se desvaneció en el olvido con el tiempo.
C1 verb ˈɔː.kɪ.streɪ.tɪd

orchestrated

orquestado
Meaning
Planned or coordinated carefully and deliberately.
Example
The attacks were orchestrated with precision.
Los ataques fueron orquestados con precisión.
C1 noun /əbˈdʒɛktər/

objector

opositor
Meaning
a person who expresses opposition or disapproval to something
Example
The objector raised his concerns during the town meeting.
El opositor expresó sus preocupaciones durante la reunión del consejo.
B2 adjective ˌɒp.ərˈeɪ.ʃən.əl

operational

operativo
Meaning
In working order; ready for use.
Example
The space project will be operational by 2025.
El proyecto espacial estará operativo para 2025.
B1 noun ˌɔː.ɡən.aɪˈzeɪ.ʃənz

organizations

organizaciones
Meaning
Organized groups of people with a particular purpose
Example
Organizations play a key role in policymaking.
Las organizaciones desempeñan un papel clave en la toma de decisiones políticas.
C2 verb ˈɑːb.fə.skeɪt

obfuscate

ofuscar, oscurecer, confundir
Meaning
Render obscure, unclear, or unintelligible.
Example
Politicians often obfuscate facts to mislead people.
Los políticos a menudo ofuscan los hechos para engañar a la gente.
A2 noun /ˈɒm.lət/

Omelet

tortilla
Meaning
a dish made from beaten eggs cooked in a frying pan and often folded around a filling
Example
She made a cheese omelet for breakfast.
Ella hizo una tortilla de queso para el desayuno.
B2 verb /ˌoʊvərˈduː/

overdo

exagerar
Meaning
to do something too much; to exaggerate or carry to excess
Example
Don't overdo the exercise on your first day at the gym.
No exageres con el ejercicio en tu primer día en el gimnasio.
B2 noun /əbˈzɜːvər/

observer

observador
Meaning
a person who watches or notices something
Example
The observer took notes during the meeting.
El observador tomó notas durante la reunión.
B2 adjective /ˌoʊvərˈwɛlmɪŋ/

overwhelming

abrumador
Meaning
Very intense; overpowering.
Example
Large tasks can feel overwhelming.
Las grandes tareas pueden sentirse abrumadoras.
C2 adjective /ˈoʊdiəs/

odious

odioso
Meaning
extremely unpleasant or repulsive
Example
The dictator was remembered for his odious crimes.
El dictador fue recordado por sus odiosos crímenes.
B2 noun /oʊˈbiː.di.əns/

Obedience

obediencia
Meaning
compliance with an order, request, or law; submission to authority
Example
Children should show obedience to their parents.
Los niños deben mostrar obediencia a sus padres.
B2 noun /ˈoʊtˌmiːl/

oatmeal

avena cocida
Meaning
A type of porridge made from ground oats, often eaten for breakfast.
Example
She eats a bowl of oatmeal every morning for breakfast.
Ella come un tazón de avena cocida todas las mañanas para el desayuno.
B2 adverb /əˈfɪʃəli/

officially

oficialmente
Meaning
in a formal or authorized way
Example
The building was officially opened by the mayor.
El edificio fue oficialmente inaugurado por el alcalde.
C2 noun /ˈəʊpəs/

opus

obra creativa
Meaning
A creative work, especially a large and important piece of music or art.
Example
The composer considered the symphony his greatest opus.
El compositor consideró la sinfonía su mayor obra creativa.
B1 verb অকার্স

occurs

sucede
Meaning
Happens or takes place, especially as a result of something.
Example
Snowfall occurs in regions with freezing temperatures.
La nieve ocurre en regiones con temperaturas bajo cero.
B2 adjective + noun ˈɒptɪməl ˈtempərətʃər

optimal temperature

temperatura óptima
Meaning
The best or most favorable temperature for a particular purpose
Example
Winter provides optimal temperature for farming.
El invierno proporciona la temperatura óptima para la agricultura.
C1 noun /ˈɔːrθədɑːksi/

orthodoxy

ortodoxia
Meaning
traditional or generally accepted beliefs and practices
Example
The religious leader defended the orthodoxy of the faith.
El líder religioso defendió la ortodoxia de la fe.