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A2 conjunction /ʌnˈlɛs/

unless

a menos que
Meaning
except if
Example
We won't go unless it stops raining.
No iremos a menos que deje de llover.
C1 adjective /ʌnˈvɔɪst/

unvoiced

no expresado
Meaning
not expressed in speech; in phonetics, a sound produced without vocal cord vibration
Example
The student kept her opinion unvoiced during the meeting.
La estudiante mantuvo su opinión no expresada durante la reunión.
C2 verb /ʌpˈhiːv/

upheave

levantar
Meaning
to lift or raise something forcefully; to cause to rise suddenly
Example
The workers had to upheave the heavy stone to clear the path.
Los trabajadores tuvieron que levantar la piedra pesada para despejar el camino.
B2 adjective /ʌnˈθɪŋkəbl/

Unthinkable

inimaginable
Meaning
impossible to conceive or imagine; beyond belief or consideration
Example
It was unthinkable that such a tragedy could happen in our peaceful town.
Era inimaginable que tal tragedia pudiera ocurrir en nuestra tranquila ciudad.
A1 interjection /ʌ/

uh

eh
Meaning
a sound people make when they hesitate or are unsure what to say next.
Example
Uh, I’m not sure if that’s the right answer.
Eh, no estoy seguro de si esa es la respuesta correcta.
B2 adjective /ʌnˈsiːn/

Unseen

invisible; no visto ni notado anteriormente
Meaning
not previously seen or noticed; invisible; hidden
Example
The unseen forces of nature can be very powerful.
Las fuerzas invisibles de la naturaleza pueden ser muy poderosas.
A2 adjective /ʌnˈhel.θi/

Unhealthy

insalubre; no saludable
Meaning
harmful to health; not in good health; detrimental to well-being
Example
Eating too much fast food is unhealthy for your body.
Comer demasiada comida rápida es insalubre para tu cuerpo.
A2 adjective /ˈjuːs.ləs/

Useless

inútil
Meaning
having no beneficial purpose; not useful
Example
This broken computer is completely useless.
Esta computadora rota está completamente inútil.
B2 adjective /ʌnˌkənˈfɜːmd/

Unconfirmed

no confirmado; no verificado;
Meaning
not confirmed as true or definite; not verified or substantiated
Example
The report remains unconfirmed until we receive official verification.
El informe sigue sin confirmar hasta que recibamos la verificación oficial.
C1 adjective /ˈʌndərhænd/

underhand

engañoso
Meaning
done secretly and dishonestly; deceitful
Example
The politician was accused of using underhand tactics to win the election.
El político fue acusado de usar tácticas engañosas para ganar las elecciones.
B2 adjective /ʌnˈdʒʌst/

Unjust

injusto; incorrecto
Meaning
not fair or right; morally wrong
Example
The punishment was unjust for such a minor offense.
El castigo fue injusto por tal pequeña ofensa.
C1 adjective /juːˈbɪkwɪtəs/

ubiquitous

ubiquito
Meaning
Existing or being everywhere at the same time.
Example
Social media has become ubiquitous among young people.
Las redes sociales se han vuelto ubicuas entre los jóvenes.
B2 adjective /ʌnˈkɒmən/

uncommon

poco común
Meaning
rare, unusual, or remarkable
Example
It is uncommon to see snow in this region.
Es raro ver nieve en esta región.
B2 adjective /ʌnprɪˈpɛrd/

Unprepared

despreparado
Meaning
not ready or able to deal with something
Example
He was unprepared for the difficult exam.
Él estaba desprevenido para el examen difícil.
C1 adjective /ˌʌnɪnˈhɪbɪtɪd/

uninhibited

desinhibido
Meaning
Not restrained or restricted; free in behavior or expression.
Example
She gave an uninhibited laugh at the joke.
Ella dio una risa desinhibida al chiste.
B2 adjective /ʌnˈlɪmɪtɪd/

unlimited

ilimitado
Meaning
without any limits or restrictions
Example
The internet plan offers unlimited data for the whole month.
El plan de internet ofrece datos ilimitados durante todo el mes.
C2 adjective /ˈɜːrsaɪn/

ursine

osoide
Meaning
Relating to or resembling a bear.
Example
The man’s ursine strength amazed everyone.
La fuerza osoide del hombre sorprendió a todos.
C1 adjective /ˌʌndərɪkˈspoʊzd/

underexposed

poco expuesto, descuidado
Meaning
insufficiently exposed to light (in photography) or not given enough attention
Example
The photo was underexposed and looked too dark.
La foto estaba poco expuesta y se veía demasiado oscura.
C1 noun /ˈʌp.tɜːn/

upturn

mejora
Meaning
An improvement or upward trend in a situation, especially in business or economy.
Example
The company experienced an upturn in sales last quarter.
La empresa experimentó una mejora en las ventas el último trimestre.
B2 verb ˈjuːnɪfaɪ

unify

unificar
Meaning
To make or become united, uniform, or whole; to bring together into a single unit.
Example
Adolescents unify with peers for social acceptance.
Los adolescentes se unifican con sus compañeros para la aceptación social.
C2 noun /ˈʌndərlɪŋ/

underling

subordinado
Meaning
a person of low rank or importance; a subordinate
Example
The manager ordered his underlings to finish the task quickly.
El gerente ordenó a sus subordinados terminar la tarea rápidamente.
A1 adverb /ʌp/

up

arriba
Meaning
towards a higher position or level
Example
He climbed up the ladder quickly.
Él subió rápidamente la escalera.
A1 verb /juːz/

use

utilizar
Meaning
to employ something for a purpose; to take advantage of
Example
I use my computer for work and entertainment.
Yo uso mi computadora para trabajar y entretenerme.
C2 noun /ʌnˈkloʊðɪŋ/

unclothing

desvestirse
Meaning
the act or process of removing clothing
Example
The child quickly ran inside for unclothing after playing in the mud.
El niño corrió rápidamente adentro para desvestirse después de jugar en el barro.
C1 adjective /ʌnˈhoʊli/

Unholy

impío; perverso; profano
Meaning
wicked; sinful; profane
Example
The unholy alliance between the two companies caused public outrage.
La alianza impía entre las dos compañías causó indignación pública.
C1 adjective /ʌnˈsɪvəlaɪzd/

Uncivilized

incivilizado; salvaje;
Meaning
not developed in terms of civilization; lacking social organization and culture; barbarous
Example
The explorers encountered an uncivilized tribe deep in the Amazon rainforest.
Los exploradores encontraron una tribu incivilizada en lo profundo de la selva amazónica.
B2 adjective /ʌnˈriːzənəbəl/

unreasonable

irrazonable
Meaning
not guided by reason or fairness; excessive or extreme beyond what is acceptable
Example
The manager made an unreasonable demand that no one could realistically meet.
El gerente hizo una exigencia irrazonable.
C1 adjective /ˌʌndərˈsteɪtɪd/

understated

subestimado
Meaning
Presented in a subtle and restrained way.
Example
She wore an elegant but understated dress.
Ella llevaba un vestido elegante pero subestimado.
C2 adjective /ˌʌn.rɪˈdʒɛn.ər.ət/

unregenerate

intransigente
Meaning
Not reformed or showing no signs of change; stubbornly refusing to reform or repent.
Example
He remained an unregenerate opponent of progress.
Siguió siendo un oponente intransigente del progreso.
C2 noun /ˈʌŋɡwənt/

unguent

ungüento
Meaning
A soothing or healing ointment applied to the skin.
Example
The doctor applied an unguent to heal the burn.
El doctor aplicó un ungüento para sanar la quemadura.
B2 adjective /ʌnˈraɪp/

Unripe

inmaduro
Meaning
not fully developed or matured; not ready to be eaten
Example
The unripe bananas will turn yellow in a few days.
Las bananas no maduras se pondrán amarillas en unos días.
C2 adjective /ʌnˈmɪtɪɡeɪtɪd/

unmitigated

completo
Meaning
absolute; not lessened or moderated
Example
The meeting was an unmitigated disaster.
La reunión fue un desastre completo.
B2 adjective /ʌnˈiːkwəl/

Unequal

desigual; injusto;
Meaning
not the same in quantity, size, or value; not fair or just
Example
The distribution of wealth is unequal in many countries.
La distribución de la riqueza es desigual en muchos países.
B1 noun /ˌʌnɪmˈplɔɪmənt/

Unemployment

desempleo
Meaning
the state of being unemployed; lack of paid work
Example
The unemployment rate has increased significantly this year.
La tasa de desempleo ha aumentado significativamente este año.
C1 verb /ʌnˈkɔrk/

uncork

destapar
Meaning
To remove the cork from a bottle; to open a bottle, especially of wine
Example
He uncorked the wine and poured a glass for everyone.
Destapó el vino y sirvió un vaso para todos.
C2 adjective /ʌnˈkɒnʃənəbl/

unconscionable

injustificable
Meaning
shockingly unfair or unreasonable
Example
The company made unconscionable profits from the crisis.
La empresa hizo ganancias injustificables durante la crisis.
B1 noun /ʌnˈhæp.i.nəs/

unhappiness

infelicidad
Meaning
the state of being unhappy; sadness or dissatisfaction
Example
Her constant unhappiness affected everyone around her.
Su constante infelicidad afectaba a todos a su alrededor.
C2 noun /ˈʌm.brə/

Umbra

sombra completa, la región oscura del centro de una mancha solar
Meaning
the fully shaded inner region of a shadow cast by an opaque object; the dark center of a sunspot
Example
During the eclipse, we stood in the moon's umbra.
Durante el eclipse, nos paramos en la umbra de la luna.
B2 verb /ˌʌndərˈmaɪn/

undermine

socavar
Meaning
to gradually weaken or damage something or someone
Example
Constant criticism can undermine a child's confidence.
La crítica constante puede socavar la confianza de un niño.
C1 verb /ˌʌndərˈsɛl/

undersell

vender a un precio más bajo
Meaning
to sell something at a lower price than competitors or to downplay the value of something
Example
The shop undersold its rivals by offering huge discounts.
La tienda vendió a sus rivales a un precio más bajo ofreciendo grandes descuentos.
B1 adjective /ˈɜːrdʒənt/

Urgent

urgente
Meaning
requiring immediate action or attention; pressing
Example
The patient needs urgent medical attention.
El paciente necesita atención médica urgente.
A1 noun /ˌjuːnɪˈvɜːrsɪti/

university

universidad
Meaning
an institution of higher education and research, which grants academic degrees
Example
She is studying law at the university.
Ella está estudiando derecho en la universidad.
C2 adjective /ˌʌnəˈʃʊəd/

unassured

inseguro
Meaning
Lacking confidence or certainty.
Example
She gave an unassured answer during the interview.
Ella dio una respuesta insegura durante la entrevista.
B2 adjective /ʌnˈlɔːfl/

Unlawful

ilegal; ilícito
Meaning
not authorized by law; illegal
Example
The court declared the search unlawful.
El tribunal declaró que la búsqueda era ilegal.
B2 adjective /ʌnˈprɒf.ɪ.tə.bl̩/

Unprofitable

no rentable
Meaning
not yielding profit or gain; not producing financial benefit
Example
The unprofitable business was forced to close down after three years.
El negocio no rentable se vio obligado a cerrar después de tres años.
A2 verb /ʌpˈset/

upset

molestar
Meaning
to make someone worried, sad, or angry; to disturb
Example
The bad news upset everyone.
La mala noticia upset a todos.
C2 adjective /ʌnˈʌtərəbl/

unutterable

inefable
Meaning
Too great, intense, or awful to be expressed or described in words.
Example
She was filled with unutterable joy at the news of her success.
Ella estaba llena de una alegría inefable al escuchar las noticias de su éxito.
A1 adjective /ˈjuːs.fəl/

Useful

útil; práctico
Meaning
having a beneficial purpose; practical
Example
This tool is very useful for fixing problems.
Esta herramienta es muy útil para resolver problemas.
B2 adjective /ʌnˈbiːtən/

Unbeaten

invicto; no derrotado
Meaning
not defeated; having never lost; undefeated
Example
The team remains unbeaten this season.
El equipo sigue invicto esta temporada.
B2 adjective /ʌnˈhɛlpfəl/

unhelpful

poco útil
Meaning
not providing help or support; making a situation harder rather than easier
Example
His unhelpful attitude slowed down the entire project.
Su actitud poco útil retrasó todo el proyecto.
B2 adjective /ˌʌndɪˈsaɪdɪd/

Undecided

indeciso; incierto
Meaning
not having made a decision; uncertain
Example
She was undecided about which college to attend.
Ella estaba indecisa sobre qué universidad asistir.
C2 noun /ˈʌp.wel.ɪŋ/

upwelling

Fenómeno oceanográfico que implica el movimiento de agua densa, fría y rica en nutrientes hacia la superficie del océano.
Meaning
An oceanographic phenomenon that involves wind-driven motion of dense, cooler, and nutrient-rich water towards the ocean surface.
Example
Upwelling brings nutrients to the ocean surface.
El upwelling lleva nutrientes a la superficie del océano.
B1 adjective /ʌnˈseɪf/

Unsafe

inseguro; peligroso;
Meaning
involving or causing danger or risk; not protected from harm
Example
It is unsafe to walk alone in this neighborhood at night.
Es inseguro caminar solo en este vecindario por la noche.
C2 verb /ˈʌndjʊleɪt/

undulate

ondular
Meaning
To move with a smooth, wave-like motion.
Example
The snake undulated across the sand.
La serpiente onduló a través de la arena.
C2 adjective /ˌʌnsɛrəˈmoʊniəs/

unceremonious

sin ceremonias/rudo
Meaning
Done without formality or courtesy; abrupt or rude.
Example
He made an unceremonious exit from the party.
Él hizo una salida sin ceremonias de la fiesta.
C1 adjective /ˌʌnəˈfɛktɪd/

unaffected

inafectado, genuino
Meaning
Not influenced or touched by something; genuine and natural.
Example
He remained unaffected by the criticism and kept working hard.
Él permaneció sin verse afectado por la crítica y siguió trabajando duro.
B2 adjective /ˌʌnəˈvɔɪdəbəl/

Unavoidable

Inevitable; que no se puede evitar; obligatorio
Meaning
cannot be avoided; certain to happen; inevitable
Example
The meeting is unavoidable, so we must attend.
La reunión es inevitable, así que debemos asistir.
B2 adjective /ˌʌnˈkɔːrdɪneɪtɪd/

uncoordinated

descoordinado
Meaning
lacking coordination, not well-organized or clumsy in movement
Example
His movements were uncoordinated, making him prone to accidents.
Sus movimientos eran descoordinados, lo que lo hacía propenso a accidentes.
B2 adjective /ˈʌt.ɚ/

Utter

completo; absoluto; total
Meaning
complete; absolute; total
Example
The movie was an utter disaster at the box office.
La película fue un desastre total en la taquilla.
C1 adjective /ˈʌpərˌmoʊst/

uppermost

más alto
Meaning
situated at the highest place or most important
Example
Her family's safety was uppermost in her mind during the crisis.
La seguridad de su familia era lo más importante en su mente durante la crisis.
B1 verb /ʌnˈræp/

unwrap

desenvolver
Meaning
remove wrapping or covering from something; reveal something gradually or clearly
Example
She carefully unwrapped the gift with excitement.
Ella desenvolvió el regalo con cuidado y emoción.
C1 adjective /ʌnˈkwes.tʃən.ə.bl̩/

Unquestionable

indiscutible; seguro
Meaning
not able to be disputed or doubted; certain and beyond doubt
Example
Her honesty and integrity are unquestionable qualities.
Su honestidad e integridad son cualidades indiscutibles.
B1 noun /ˈjuːnɪvɜːrs/

Universe

universo
Meaning
all existing matter and space; the cosmos
Example
Scientists study the universe to understand its mysteries.
Los científicos estudian el universo para entender sus misterios.
C1 adjective /ʌnˈsəʊʃəl/

unsocial

antisocial
Meaning
not enjoying the company of others; avoiding social interaction; contrary to social norms
Example
He prefers unsocial hours so he can work alone without interruptions.
Prefiere horarios antisociales para trabajar solo.
B2 adverb /ʌnˈkɒnʃəsli/

unconsciously

inconscientemente
Meaning
without being aware of one's actions or surroundings
Example
She unconsciously tapped her foot to the rhythm of the music.
Ella inconscientemente movía el pie al ritmo de la música.
C2 verb /juˈzɜrp/

usurp

usurpar
Meaning
to take someone's position of power illegally or by force
Example
The general tried to usurp the king's throne.
El general intentó usurpar el trono del rey.
B2 adjective /ʌnprəˈdʌk.tɪv/

Unproductive

improductivo; ineficaz
Meaning
not achieving much; not producing good results
Example
The meeting was unproductive and wasted everyone's time.
La reunión fue improductiva y desperdició el tiempo de todos.
C2 adjective /ˈʌndjʊleɪtɪŋ/

undulating

ondulante
Meaning
Having a smoothly rising and falling form or motion like waves.
Example
We drove through undulating hills.
Condujimos por colinas onduladas.
A2 noun /ˈjuːzər/

user

usuario
Meaning
a person who uses or operates something
Example
He is a frequent user of this app.
Él es un usuario frecuente de esta aplicación.
B2 noun /ʌnˈsɜːrtənti/

Uncertainty

incertidumbre; duda o falta de certeza
Meaning
the state of being uncertain; doubt or lack of sureness
Example
The uncertainty about the weather delayed our trip.
La incertidumbre sobre el clima retrasó nuestro viaje.
C1 adjective /ʌnˈduː/

Undue

excesivo; inapropiado; más de lo necesario o adecuado
Meaning
excessive; inappropriate; more than is necessary or proper
Example
The teacher complained about undue pressure from parents.
El maestro se quejó de la presión excesiva de los padres.
C1 adjective /ˌʌnˈpɑr.də.nə.bəl/

Unpardonable

imperdonable
Meaning
too bad to be forgiven; inexcusable
Example
His betrayal of trust was an unpardonable offense.
Su traición fue un delito imperdonable.
B1 adjective /ˌʌndərˈstændəbl/

understandable

comprensible
Meaning
Able to be understood; reasonable or justifiable.
Example
Her reaction was understandable given the situation.
Su reacción fue comprensible dada la situación.
C2 adjective /ˌʌltrəˈmɒnteɪn/

ultramontane

partidario del Papa
Meaning
beyond the mountains, especially referring to support for the Pope over local church authority
Example
The debate highlighted the ultramontane position in church politics.
El debate destacó la posición ultramontana en la política eclesiástica.
C2 adjective /ˌʌnəˈsweɪdʒd/

unassuaged

inquieto
Meaning
Not made less intense or relieved; unrelieved.
Example
His grief remained unassuaged despite the passage of time.
Su dolor permaneció inquieto a pesar del paso del tiempo.
B1 adjective /ʌnɪmˈplɔɪd/

Unemployed

desempleado
Meaning
without a job; not having paid work
Example
He has been unemployed for six months now.
Él ha estado desempleado durante seis meses.
B1 adjective /ʌnˈsɜːrtən/

Uncertain

incierto
Meaning
not able to be relied on; not known or definite; not having reliable knowledge
Example
I am uncertain about my future career plans.
Estoy incierto sobre mis planes futuros de carrera.
B2 adjective /ʌnˈhɜːrt/

unhurt

ileso
Meaning
Not injured or harmed.
Example
She walked away from the accident unhurt.
Ella caminó lejos del accidente sin sufrir daño.
C1 adjective /ˌʌndərˈsaɪzd/

undersized

de tamaño pequeño
Meaning
Smaller than the usual or expected size.
Example
The undersized puppy struggled to keep up with its siblings.
El perrito de tamaño pequeño luchaba por mantenerse al día con sus hermanos.
B2 adjective /ˌʌndɪˈzaɪərəbl/

Undesirable

indeseable; perjudicial; desagradable
Meaning
not wanted or wished for; harmful or unpleasant
Example
The new policy had several undesirable consequences.
La nueva política tuvo varias consecuencias indeseables.
B1 preposition, adverb, adjective /ˌʌndərˈniːθ/

underneath

debajo, bajo
Meaning
Located directly below or beneath something
Example
The keys were hidden underneath the pile of papers.
Las llaves estaban escondidas debajo de la pila de papeles.
C2 adjective /ʌnəˈpiːzd/

unappeased

insatisfecho
Meaning
Not satisfied or calmed; still feeling discontent or anger
Example
Despite the apology, she remained unappeased.
A pesar de la disculpa, ella permaneció insatisfecha.
B1 noun /juːˈten.səlz/

Utensils

utensilios
Meaning
tools or implements used for cooking, eating, or serving food
Example
Please wash all the cooking utensils after preparing dinner.
Por favor, lave todos los utensilios de cocina después de preparar la cena.
A2 noun /ˈʌndərwɛr/

Under wear

ropa interior
Meaning
clothing worn under other clothes, next to the skin
Example
She bought new underwear from the department store.
Ella compró nuevo ropa interior en la tienda departamental.
B2 adjective /ʌnˈhɜːd/

Unheard

no escuchado; desconocido
Meaning
not heard or listened to; not given a hearing; unknown or unfamiliar
Example
His complaints went unheard by the management.
Sus quejas pasaron desapercibidas por la gerencia.
B1 adjective /ˌʌnɪmˈpɔːrtənt/

unimportant

sin importancia
Meaning
not having much value, significance, or influence
Example
The detail seemed unimportant compared to the main issue.
El detalle parecía sin importancia en comparación con el problema principal.
A1 adverb /ˈjuː.ʒu.ə.li/

Usually

habitualmente; usualmente
Meaning
in most cases; generally; as a rule
Example
I usually wake up at 7 AM every morning.
Normalmente me despierto a las 7 AM cada mañana.
A2 adjective /ʌnˈkʌmf.tə.bəl/

Uncomfortable

incómodo; incómoda
Meaning
causing or feeling slight pain or physical discomfort; making someone feel embarrassed, awkward, or anxious
Example
The chair was so uncomfortable that I couldn't sit in it for more than ten minutes.
La silla era tan incómoda que no pude sentarme en ella por más de diez minutos.
C1 noun /ʌpˈhiːvəl/

upheaval

upheaval
Meaning
a violent or sudden change or disruption to something
Example
The company faced a major upheaval after the sudden resignation of its CEO.
La empresa enfrentó un gran desorden tras la repentina renuncia de su CEO.
C2 adjective /ʌnˈlɛtəd/

unlettered

analfabeto
Meaning
lacking education or the ability to read and write; illiterate
Example
The unlettered villagers relied on oral traditions to preserve their history.
Los aldeanos analfabetos dependían de las tradiciones orales para preservar su historia.
C1 adjective /ʌnˈtʌtʃəbəl/

Untouchable

intocable; más allá de la crítica o el ataque
Meaning
not able to be touched or affected; beyond criticism or attack
Example
The CEO seemed untouchable despite the scandal.
El CEO parecía intocable a pesar del escándalo.
B1 adjective /ˌʌnsəkˈsesfl/

Unsuccessful

fallido; no logrado;
Meaning
not achieving desired aims or results; failing to accomplish a purpose
Example
His unsuccessful attempt to climb the mountain left him disappointed.
Su intento fallido de escalar la montaña lo dejó decepcionado.
C1 adjective /ˌʌnəˈkaʊntəbl/

unaccountable

inexplicable
Meaning
Not able to be explained or justified.
Example
She felt an unaccountable fear as she entered the dark room.
Ella sintió un miedo inexplicable al entrar en la habitación oscura.
C1 adjective /ʌnˈfɛtərd/

unfettered

libre
Meaning
not restricted or confined; free
Example
The artist enjoyed unfettered freedom of expression.
El artista disfrutó de la libertad ilimitada de expresión.
B2 adjective /ˌʌnɪˈmædʒənəbəl/

Unimaginable

inimaginable
Meaning
impossible to conceive; beyond imagination
Example
The scale of destruction was unimaginable until we saw it firsthand.
La escala de la destrucción era inimaginable hasta que lo vimos de primera mano.
B2 adjective /ˌʌndɪˈveləpt/

Undeveloped

no desarrollado; inmaduro; primitivo
Meaning
not yet developed; immature or primitive
Example
The undeveloped land was later turned into a park.
La tierra no desarrollada fue luego convertida en un parque.
C2 adjective /ʌnˈflæpəbəl/

unflappable

imperturbable
Meaning
calm and composed, especially in difficult situations
Example
Despite the crisis, he remained unflappable and confident.
A pesar de la crisis, se mantuvo imperturbable y confiado.
C1 adjective /ˌʌnrɪˈfaɪnd/

unrefined

sin refinar
Meaning
not processed or purified; lacking polish or sophistication
Example
The unrefined oil must be processed before it can be used as fuel.
El aceite sin refinar debe procesarse antes de usarse como combustible.
C1 noun /ʌnˈfeɪθfʊlnəs/

unfaithfulness

infidelidad
Meaning
the quality of being disloyal or not faithful; breach of trust or fidelity
Example
His unfaithfulness led to the end of their marriage.
Su infidelidad llevó al fin de su matrimonio.
B2 verb /ˌʌndərˈɛstɪmeɪt/

underestimate

subestimar
Meaning
To judge something as less important or smaller than it really is.
Example
Never underestimate the power of teamwork.
Nunca subestimes el poder del trabajo en equipo.
C2 adjective /ˌʌnɪkˈsɛpʃənəbl/

unexceptionable

irreprochable
Meaning
Not open to objection; acceptable and unobjectionable
Example
His behavior was unexceptionable throughout the event.
Su comportamiento fue irreprochable durante el evento.
A2 adjective /ʌnˈhæp.i/

Unhappy

descontento; triste
Meaning
not happy; feeling sad or displeased; unfortunate or undesirable
Example
He was unhappy with the results of his exam.
Él estaba descontento con los resultados de su examen.
C1 adjective /ˌʌnrɪˈkwaɪtɪd/

unrequited

no correspondido
Meaning
Not returned or reciprocated, especially in the context of love or affection.
Example
He suffered from unrequited love for years.
Él sufrió de amor no correspondido durante años.
B2 adjective /ˌʌnprɪˈdɪktəbəl/

unpredictable

impredecible
Meaning
not able to be predicted; changing suddenly and unexpectedly
Example
The weather in this region is highly unpredictable.
El clima en esta región es muy impredecible.
B2 adjective /ˈʌpˌhɪl/

Uphill

difícil; que requiere gran esfuerzo; inclinado hacia arriba
Meaning
difficult; requiring great effort; sloping upward
Example
Learning a new language can be an uphill battle.
Aprender un nuevo idioma puede ser una batalla difícil.
B2 adjective /ʌnˈɡreɪt.fəl/

Ungrateful

ingrato
Meaning
not feeling or showing thanks for something done or given; not appreciating kindness
Example
She felt he was ungrateful for all the help she had given him.
Ella sintió que él era ingrato por toda la ayuda que le había dado.
B2 adjective /ʌnˈnætʃərəl/

Unnatural

antinatural
Meaning
not existing in nature; artificial; forced
Example
The actor's smile looked unnatural and forced.
La sonrisa del actor parecía antinatural y forzada.
B2 adverb /ˈɜːrdʒəntli/

urgently

urgentemente
Meaning
in a way that requires immediate attention or action
Example
The patient urgently needs medical attention.
El paciente necesita atención médica urgentemente.
A2 noun /ʌmˈbrɛlə/

umbrella

paraguas
Meaning
A device used for protection against rain or sun, typically consisting of a collapsible canopy mounted on a central rod.
Example
She opened her umbrella as it started to rain.
Ella abrió su paraguas cuando empezó a llover.
B1 adjective /ʌnˈkʊkt/

uncooked

crudo
Meaning
Not cooked; in a raw state.
Example
Eating uncooked meat can be dangerous.
Comer carne cruda puede ser peligroso.
A1 preposition/conjunction /ʌnˈtɪl/

until

hasta
Meaning
up to the time of
Example
I will wait until you come back.
Esperaré hasta que regreses.
B1 noun /ˈjuːs.fəl.nəs/

Usefulness

utilidad
Meaning
the quality of being useful; practical value or helpfulness
Example
The usefulness of this tool became apparent during the project.
La utilidad de esta herramienta se hizo evidente durante el proyecto.
C1 adjective /ˌʌnsəˈfɪstɪˌkeɪtɪd/

unsophisticated

no sofisticado
Meaning
Lacking worldly experience, refinement, or complexity.
Example
The villagers led an unsophisticated but happy life.
Los aldeanos llevaban una vida no sofisticada pero feliz.
C2 verb /ʌnˈɑːrm/

unarm

desarmar
Meaning
to remove weapons from someone or to deprive of means of attack or defense
Example
The soldiers were ordered to unarm the prisoners.
Se ordenó a los soldados desarmar a los prisioneros.
B2 adjective /ʌnˈdɪvaɪdɪd/

Undivided

Indiviso; completo; no separado ni dividido
Meaning
whole; complete; not separated or split
Example
The team showed undivided attention to the coach's instructions.
El equipo mostró atención indivisa a las instrucciones del entrenador.
C1 adjective /ʌnˈfɔːltərɪŋ/

unfaltering

inquebrantable
Meaning
Steady and resolute; not weakening or hesitating
Example
She continued with unfaltering determination.
Ella continuó con una determinación inquebrantable.
B2 adverb juːˈnæn.ɪ.məs.li

unanimously

unánimemente
Meaning
With the agreement of all people involved; without opposition.
Example
The proposal was unanimously accepted.
La propuesta fue aceptada unánimemente.
C1 adjective ˌʌn.pəˈtɜːbd

unperturbed

no preocupado o perturbado por algo; calmado y compuesto
Meaning
Not worried or disturbed by something; calm and composed.
Example
She remained unperturbed despite the challenges.
Ella permaneció tranquila a pesar de los desafíos.
C2 adjective /ˌʌnpriːpəˈzɛsɪŋ/

unprepossessing

poco atractivo
Meaning
not attractive or appealing in appearance
Example
Despite his unprepossessing looks, he was very kind and intelligent.
A pesar de sus poco atractivos rasgos, era muy amable e inteligente.
C2 adjective /ʌpˈrɔːr.i.əs/

uproarious

sumamente cómico
Meaning
Extremely funny or noisy; causing loud laughter or commotion.
Example
The comedian's jokes were absolutely uproarious.
Los chistes del comediante fueron absolutamente sumamente cómicos.
C1 adjective /ʌnˈtʃælɪndʒd/

Unchallenged

incontestable; aceptado sin oposición; sin rival
Meaning
not disputed or questioned; accepted without opposition; having no rival
Example
He remained the unchallenged champion for five years.
Él permaneció como el campeón indiscutido durante cinco años.