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Wordabulary

Word library

8,130 words, searchable by word, definition, part of speech, and CEFR level.

obtuse Adjective C1

Slow to understand something obvious, or, of an angle, greater than 90 degrees.

obtuse angle Noun B1

An angle that measures more than ninety degrees but less than a hundred eighty degrees.

obviate Verb C1

To remove a need or difficulty; to make something unnecessary.

obvious Adjective A2

Easy to see or understand, leaving little doubt.

occasion Noun B1

A particular time when something happens, or a special event.

occlude Verb C2

To block or close off a passage or opening.

occult Adjective C1

Relating to supernatural or magical powers and practices.

occupation Noun A2

A person's job or profession, or the act of a country's military controlling another territory.

occupy Verb A2

To live or work in a place, or to fill up space or time, or to take control of a place by force.

occur Verb B1

To happen, especially something that isn't planned.

occurrence Noun A2

Something that happens, especially an event that is unusual or notable.

ocean Noun A1

One of the huge areas of salt water that cover most of the Earth.

oceanic crust Noun B2

The thin, dense layer of the earth's crust that lies beneath the oceans.

oceanic trench Noun B1

A long, narrow, extremely deep depression on the ocean floor, usually formed where one tectonic plate slides beneath another.

octagon Noun A1

A flat shape with eight straight sides.

october Noun A1

The tenth month of the year, associated in many places with autumn and Halloween.

octopus Noun A1

A sea creature with a soft, rounded body and eight long arms.

odd Adjective A1

Strange or unusual, or, in mathematics, a number that cannot be divided evenly by two.

ode Noun A2

A poem that expresses strong admiration or praise for a person or thing.

odious Adjective C2

Extremely unpleasant and causing hatred or disgust.

of Preposition A1

Shows that something belongs to, is part of, or is made from something else.

off Adverb A1

Away from a place, or no longer working or connected.

off Preposition A1

Moving away from, or no longer on or touching something.

offend Verb A2

To hurt someone's feelings or upset them, often unintentionally.

offer Verb A1

To say that you are willing to give or do something for someone.

offhand Adjective C1

Said or done without careful thought, sometimes seeming careless.

office Noun A1

A room or building where people do administrative or professional work.

officer Noun A2

A person who holds a position of authority, especially in the police or armed forces.

official Adjective A2

Approved or done by someone in a position of authority, such as a government or organization.

officious Adjective C1

Too eager to give orders or to interfere in matters that are not your concern.

offset Verb B2

To balance the effect of one thing with an opposite effect.

offspring Noun A2

The young of a person, animal, or plant.

often Adverb A1

Many times, frequently.

oh Interjection A1

Used to express surprise, understanding, or other sudden emotion.

ohm Noun B1

The standard unit used to measure electrical resistance.

ohm's law Noun B2

The physics principle stating that the current through a conductor is directly proportional to the voltage across it and inversely proportional to its resistance.

oil Noun A1

A thick liquid used for cooking or for making machines run smoothly.

oink Noun A1

The sound a pig makes.

ointment Noun A2

A smooth, thick substance rubbed onto the skin to treat a wound, rash, or other problem.

ok Adjective A1

Acceptable, satisfactory, or in a reasonably good condition.

ok Interjection A1

Used to show agreement, acceptance, or acknowledgment.

okay Adjective A1

Acceptable, fine, or in a satisfactory condition.

old Adjective A1

Having lived or existed for a long time.

old-fashioned Adjective B1

No longer modern or fashionable; typical of an earlier time.

oligarchy Noun B2

A form of government in which power is held by a small group of people, often for their own benefit.

oligopoly Noun B2

A market controlled by a small number of large companies rather than many small competitors.

oligosaccharide Noun C1

A carbohydrate molecule made up of a small number of simple sugar units joined together.

olive Noun A1

A small, oval fruit that grows on trees in warm climates, eaten whole or pressed for oil.