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Level: B2-C1

100 Words Every High School Graduate Should Know

100 essential English words for academic texts, news, and professional communication — each with a clear, simple definition.

  • abjure – to promise not to do something; to give up a belief or habit
  • abrogate – to end or cancel something (like a law or agreement)
  • abstemious – not eating or drinking much; self-controlled
  • acumen – the ability to understand and make good decisions
  • antebellum – before a war, especially the American Civil War
  • auspicious – showing signs of future success; lucky
  • belie – to give a false idea about something
  • bellicose – wanting to fight or argue
  • bowdlerize – to remove parts of a book, play, or text that may be offensive
  • chicanery – using tricks to cheat or deceive people
  • chromosome – a part in cells that carries genetic information
  • churlish – rude or not polite
  • circumlocution – using too many words to say something simple
  • circumnavigate – to travel all the way around something, especially the world
  • deciduous – losing leaves every year
  • deleterious – harmful; causing damage
  • diffident – shy; not confident
  • enervate – to make someone feel weak or tired
  • enfranchise – to give someone the right to vote
  • epiphany – a sudden, clear understanding of something
  • equinox – the time when day and night are the same length
  • euro – the money used in many European countries
  • evanescent – lasting only a short time; disappearing quickly
  • expurgate – to remove bad or offensive parts from a text
  • facetious – joking in a way that is not serious
  • fatuous – silly; foolish
  • feckless – weak; not responsible
  • fiduciary – relating to trust, especially in money matters
  • filibuster – a long speech in a legislature to delay or stop a vote
  • gamete – a cell (egg or sperm) used for reproduction
  • gauche – awkward; not polite in social situations
  • gerrymander – to change the borders of an area for political advantage
  • hegemony – leadership or control by one country or group
  • hemoglobin – a substance in red blood cells that carries oxygen
  • homogeneous – all the same or similar
  • hubris – too much pride or confidence
  • hypotenuse – the longest side of a right-angled triangle
  • impeach – to accuse a government official of a crime
  • incognito – hiding your identity
  • incontrovertible – impossible to question or doubt; certain
  • inculcate – to teach an idea or habit by repeating it often
  • infrastructure – basic systems and structures like roads and bridges
  • interpolate – to add something between other things
  • irony – saying the opposite of what you mean, often for humor
  • jejune – boring; not interesting
  • kinetic – relating to movement
  • kowtow – to act in a very obedient way
  • laissez faire – the idea that government should not control business
  • lexicon – all the words used in a language or by a person
  • loquacious – very talkative
  • lugubrious – very sad or gloomy
  • metamorphosis – a big change in form or nature
  • mitosis – cell division; when one cell becomes two cells
  • moiety – one of two equal parts
  • nanotechnology – technology that works with very small things like atoms
  • nihilism – the belief that nothing has meaning or value
  • nomenclature – a system of names for things
  • nonsectarian – not related to a specific religious group
  • notarize – to have a document officially certified by a notary
  • obsequious – too eager to please or obey someone
  • oligarchy – a government run by a small group of people
  • omnipotent – having unlimited power
  • orthography – the way words are spelled
  • oxidize – to combine with oxygen
  • parabola – a special U-shaped curve in math
  • paradigm – a model or example
  • parameter – a limit or rule that controls what something is or how it works
  • pecuniary – relating to money
  • photosynthesis – how plants make food using sunlight
  • plagiarize – to copy someone else’s work and say it is yours
  • plasma – a state of matter like gas, or the liquid part of blood
  • polymer – a substance made of many small parts joined together
  • precipitous – very steep or sudden
  • quasar – a very bright and distant object in space
  • quotidian – happening every day; ordinary
  • recapitulate – to repeat the main points
  • reciprocal – given and received in return
  • reparation – payment or action to fix a wrong or damage
  • respiration – breathing
  • sanguine – cheerful; hopeful
  • soliloquy – a speech in a play where a character speaks their thoughts
  • subjugate – to bring under control; to conquer
  • suffragist – a person who works for the right to vote
  • supercilious – acting as if you are better than others
  • tautology – saying the same thing twice in different words
  • taxonomy – the science of classifying things
  • tectonic – relating to the structure of the earth’s surface
  • tempestuous – full of strong emotions or stormy
  • thermodynamics – the science of heat and energy
  • totalitarian – a government with total control over people
  • unctuous – too friendly in a way that is not sincere
  • usurp – to take power or position without the right to do so
  • vacuous – lacking ideas or intelligence
  • vehement – showing strong feeling
  • vortex – a spinning flow of air or liquid
  • winnow – to remove the unwanted parts from something
  • wrought – made or shaped by hand
  • xenophobe – a person who dislikes foreigners
  • yeoman – a farmer who owns his land; a loyal worker
  • ziggurat – an ancient, step-shaped building (temple) in Mesopotamia