Virtuous English AcademyRisk & Uncertainty — B2 English Vocabulary
This B2 vocabulary list gathers 50 upper-intermediate English words about risk & uncertainty — danger, chance and the unknown. Every word comes with a simple definition, its British-English pronunciation and a natural example sentence, so you learn each one in real context. When you are ready, open the flashcards to practise and remember them for good.
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Using risk & uncertainty words in English
Risk vocabulary is graded by strength and by register, and this page arranges it. Probability, likelihood and odds express the same idea at three levels of formality; risky, dangerous, hazardous and perilous do the same for danger. The page also covers dare, which behaves partly like a modal verb and produces one of the odder question forms in English.
What to watch out for
Probability, likelihood, odds, chance
Probability is the technical term and takes a number: a probability of 0.3. Likelihood is the general formal word: the likelihood of failure. Odds is plural and comes from betting: the odds are against us. Chance is the everyday word and is countable: a good chance of rain. All four take of before a noun.
Danger runs from risky to perilous
Risky is everyday and often means merely unwise. Dangerous is the standard neutral word. Hazardous is technical and appears in regulation: hazardous waste. Perilous is literary and would sound theatrical in a safety notice. Jeopardy is a noun — in jeopardy — with the verb jeopardise, spelled with an s in British English.
Dare behaves partly like a modal
In the fixed exclamation, dare takes no auxiliary and no to: How dare you! In negatives it can go either way: He dared not speak or He did not dare to speak. In ordinary positive statements it is a normal verb: She dared him to jump. Note also the fixed patterns take precautions, expose someone to a risk and at risk of.
Words learners mix up
Risk vocabulary distinguishes three things that ordinary English runs together: how close the danger is, what kind of unreliability you are describing, and what you did in advance about it.
How close is it?
| Word | What it actually means | In a sentence |
|---|---|---|
| imminent | About to happen, within a very short time. About timing only, and the thing may be good or bad. | A collapse looked imminent. |
| looming | Approaching and casting a shadow ahead of it. Always unwelcome, and it suggests scale as well as nearness. | A looming shortage of teachers. |
| precarious | Not about timing at all — unstable, liable to collapse at any moment. Describes a state, not an event. | The company is in a precarious financial position. |
| unforeseen | Not predicted before it happened. A judgement made afterwards, and it excuses the person who missed it. | Unforeseen delays added three months. |
The pair worth separating is imminent and precarious: the first says something will happen soon, the second that it could happen at any time without saying it will. And note eminent — distinguished — which is a different word entirely and a common misspelling of the first.
Four ways of being unreliable
| Word | What it actually means | In a sentence |
|---|---|---|
| unpredictable | You cannot say what it will do next. The most general term, and it can describe people, weather or markets. | An unpredictable opponent. |
| erratic | Moving irregularly and inconsistently, with no pattern. Implies something has gone wrong with a thing that should be steady. | His attendance became erratic. |
| random | Technically, governed by chance with no pattern at all. In statistics it is a precise property, not a synonym for odd. | Participants were assigned at random. |
| fluctuation | Regular movement up and down around a level. The noun for variation that is expected rather than alarming. | Seasonal fluctuation in demand. |
| inconclusive | Not about behaviour but about evidence — it did not settle the question either way. | The tests were inconclusive. |
Random is the one that has drifted furthest: in speech it now means surprising or irrelevant — a random comment — but in any technical or academic sentence it retains its statistical sense, and using the loose one there will read as an error.
What did you do about it in advance?
| Word | What it actually means | In a sentence |
|---|---|---|
| precaution | An action taken beforehand to prevent harm. Countable, and normally plural: take precautions. | As a precaution, the building was cleared. |
| contingency | A plan for a specific thing that might go wrong. It sits unused unless the event occurs. | They activated the contingency plan. |
| fallback | The alternative you drop to when the first choice fails. One word as a noun, two as the verb fall back on. | Print forms are the fallback if the system is down. |
| mitigate | To reduce the severity of something rather than prevent it. Accepts the risk and limits the damage. | Measures to mitigate flood damage. |
| insure | To transfer the financial loss to someone else for a fee. Specific and commercial. | The cargo was insured against fire. |
These form a ladder of ambition: a precaution tries to stop it, mitigation accepts it and limits it, a contingency plans for it, and insurance pays for it. Note also ensure (make certain) and assure (tell someone confidently), which differ from insure by one letter and a great deal of meaning.
Collocations that sound natural
Risk vocabulary is heavily idiomatic, and most of these nouns live inside one or two fixed phrases. Learning the phrase is more useful than learning the noun alone.
jeopardy
in jeopardyput in jeopardyplace the project in jeopardy
Uncountable and almost always after in. The verb jeopardise is far more common and takes a direct object.
stake
at stakehigh stakesa stake in the companystake a claim
At stake means at risk of being lost. The unrelated commercial sense is a share of ownership.
odds
against the oddsthe odds arebeat the oddsthe odds of it happening
Plural and takes a plural verb. Against the odds means succeeding despite unlikelihood.
precaution
take precautionsas a precautiona sensible precautionthe precautionary principle
The verb is take. The precautionary principle is a fixed term: act to prevent harm even without full proof.
exposure
exposure to risklimit exposurefinancial exposureexposure to the elements
Uncountable, and it takes to. In finance it means how much you stand to lose.
contingency
a contingency plancontingency arrangementsa contingency fund
Nearly always used attributively before another noun in this sense.
Formal, neutral or informal?
Several of these look like plain synonyms for dangerous and are not — two are technical, two are literary, and two carry a second meaning that has nothing to do with risk.
- dubious vs doubtfulOverlapping but distinctDoubtful means unlikely or uncertain: it is doubtful that they will agree. Dubious can mean the same about a person’s feelings — I am dubious — but its other sense is that something is of questionable quality or honesty: a dubious claim, dubious accounting.
- treacherousTwo sensesOf ground or conditions, dangerously deceptive — treacherous ice, where the danger is hidden. Of a person, disloyal and betraying trust. Both come from the idea of something that cannot be relied on.
- flukeInformalSomething good that happened by pure chance rather than skill: the goal was a fluke. Countable, informal, and slightly deflating — calling a success a fluke denies the person credit.
- menaceNoun and verb · informal edgeA threat or danger. In British English it is also used half-humorously of a person who causes trouble: that dog is a menace. The adjective menacing stays serious.
- peril / perilousLiterarySerious danger, but the word belongs to narrative and headlines rather than to reports: in grave peril, a perilous journey. A risk assessment would say hazard or danger.
- hazardousTechnical · regulatoryThe word used in safety regulation and labelling: hazardous waste, hazardous substances. Precise and impersonal, which is exactly why it appears on signage.
- foolproofInformal · overclaimsDesigned so that it cannot be used wrongly or go wrong. A strong claim and usually a hostage to fortune, which is why it appears so often just before something fails.
- cautionaryFixed phraseNearly always in a cautionary tale — a story told as a warning. Rare as a free adjective, where the ordinary word is cautious, describing the person rather than the warning.
Sentences to try
Four frames about risk. Notice how formal each choice sounds.
- The likelihood of a second failure is now very low.
- The site stores hazardous materials under strict controls.
- Cutting the budget would jeopardise the entire project.
- They took every precaution against exposure to the chemical.
Questions about risk & uncertainty vocabulary
What is the difference between probability, likelihood and odds?
They express the same idea at different levels of formality and precision. Probability is the mathematical term and pairs with numbers: a probability of 0.75, a 20% probability. Likelihood is the general formal word used in prose: the likelihood of rejection. Odds is grammatically plural and comes from betting, expressing a ratio rather than a fraction: the odds are three to one. Chance is the everyday countable word: a fair chance of success. All four take of before what might happen.
What is the difference between risky, dangerous and hazardous?
They form a register ladder. Risky is informal and often means simply unwise or uncertain rather than physically threatening: a risky investment. Dangerous is the standard neutral word for something that could cause harm. Hazardous is technical and belongs to regulation, safety documents and science: hazardous substances, hazardous waste. Perilous is literary and would sound overblown in a factual report. Choosing the right rung is largely what makes technical writing sound authentic.
Why do we say "How dare you" without "do"?
Because dare is a semi-modal verb: it retains some of the grammar of modals like can and must alongside its ordinary verb behaviour. In the fixed exclamation How dare you! it takes no auxiliary and no to, exactly as a modal would. Negatives allow both patterns: He dared not ask uses the modal grammar, while He did not dare to ask uses the ordinary one. In positive statements it behaves entirely normally: He dared to disagree. Need is the other common semi-modal in English.