CEFR Level
A polygon with eight sides and eight angles.
"The stop sign is shaped like an octagon."
A series of eight musical notes, or the interval between one musical pitch and another with double its frequency.
"The singer's voice could easily reach the higher octave."
Something strange or unusual.
"The bright pink building was an oddity in the small town."
a long, adventurous journey; a series of experiences
"Her career has been an odyssey of challenges and achievements."
a person who commits a crime or does something wrong
"The police caught the offender quickly."
Without previous thought or preparation; casual and sometimes dismissive.
"She gave an offhand reply to his serious question."
To perform official duties, especially in a ceremony or as a referee.
"The priest will officiate the wedding ceremony."
To counterbalance or compensate for something.
"The company's losses were offset by gains in other departments."
A branch or result that develops from something larger or more important.
"The startup was an offshoot of a major tech company."
a person's child or children; an animal's young
"The bird carefully fed its offspring."
A smooth, oily substance applied to the skin for healing or soothing.
"The doctor prescribed an ointment for the burn on his arm."
A small group of people having control of a country, organization, or institution.
"The nation was ruled by a wealthy oligarchy that controlled all resources."
an event regarded as a sign of future good or bad luck
"Many people consider a black cat crossing your path a bad omen."
Giving the impression that something bad or unpleasant is going to happen.
"Dark clouds gave an ominous sign of an approaching storm."
The act of leaving out or excluding something; something that has been left out.
"Her omission of important details caused confusion."
present everywhere at the same time
"In the digital age, social media feels omnipresent in our lives."
eating both plants and animals
"Humans are generally considered omnivorous creatures."
involving a great deal of effort, difficulty, or burden
"Fulfilling the contract proved to be an onerous task for the company."
The beginning of something, especially something unpleasant.
"The onset of winter brought cold winds and snow."
A fierce or destructive attack.
"The village faced an onslaught of enemy forces."
A duty or responsibility, especially a heavy one.
"The onus is on the government to provide relief to the victims."
not transparent or translucent; difficult to see through or understand
"The windows were opaque with steam."
functioning, having effect, or relating to a secret agent or worker
"The new law is now operative across the country."
Happening at a suitable or convenient time.
"She arrived at an opportune moment to help."
A person who takes advantage of situations for personal gain, often disregarding principles.
"He is seen as an opportunist who always puts his interests first."
To keep someone in subservience and hardship by unjust treatment.
"The regime continued to oppress its citizens."
cruel or unjust treatment or exercise of authority; the state of being subject to harsh treatment
"The people fought against political oppression."
Harsh and authoritarian; overwhelming; causing distress; tyrannical;
"The oppressive heat made it difficult to work outside during the summer."
Relating to the eye or vision.
"The optic nerve carries signals from the eye to the brain."
related to or used in seeing or sight
"The optical illusion fooled everyone at the exhibition."
The branch of physics dealing with light and vision.
"She studied optics to understand how lenses work."
In the most effective or efficient way possible.
"Tasks should be allocated optimally for maximum output."
The action of making the best or most effective use of a situation or resource.
"The company focused on optimization of resources to maximize profits."
Make the best or most effective use of a situation, opportunity, or resource.
"They optimized the software for faster performance."
Made as effective, perfect, or functional as possible.
"Optimized irrigation techniques conserve water in farming."
The most favorable condition or level for growth, success, or productivity.
"This room temperature provides the optimum conditions for plant growth."
A healthcare professional who examines eyes and prescribes corrective lenses.
"The optometrist prescribed new glasses for her."
The practice or profession of examining the eyes and prescribing corrective lenses.
"She studied optometry at the university to become an eye specialist."
A person or source considered to provide wise and insightful advice or prophecy.
"In ancient Greece, people visited the oracle at Delphi for guidance."
A person who delivers formal speeches with skill and eloquence
"The orator captivated the audience with his eloquence."
The art of formal public speaking, often with eloquence and persuasion.
"The politician's oratory impressed the crowd."
Plan or coordinate the elements of a situation to produce a desired effect.
"He successfully orchestrated the company's expansion."
Planned or coordinated carefully and deliberately.
"The attacks were orchestrated with precision."
a diverse family of flowering plants known for their exotic and often fragrant flowers
"The white orchid on the windowsill bloomed for months."
To officially make someone a priest or minister; to decree or order something officially.
"The bishop will ordain three new priests this Sunday."
A very difficult or painful experience, often lasting for a long time.
"The survivors went through a terrible ordeal after the earthquake."
Relating to the order or position of something in a sequence (first, second, third, etc.).
"The ordinal number 'third' indicates position in a sequence."
An authoritative rule, law, or decree issued by a city, town, or authority.
"The city council passed an ordinance banning smoking in public parks."
to align or position something relative to a particular point or direction
"The map helps tourists orient themselves in the city."
