# probability

/ˌpɹɑbəˈbɪɫəˌti/ (US) · /pɹˌɒbəbˈɪlɪti/ (UK)

Source: https://englishreference.com/word/probability
Updated: 2026-06-19

## Senses

### 1. likelihood

noun · CEFR B2

the chance that something will happen or is true.

For teachers: the quality or state of being probable; the extent to which something is likely to happen.

- There is a high probability of rain this afternoon, so take an umbrella.
- The probability of a successful merger remains high, provided that both boards agree on the final valuation by the end of the quarter.

### 2. mathematical value

noun · CEFR B2 · Technical

a number between 0 and 1 that shows exactly how likely something is.

For teachers: a precise numerical measure of the likelihood of an event, where 0 indicates impossibility and 1 indicates certainty.

- In this game, the probability of drawing a red card is exactly fifty percent.
- The algorithm calculates the probability of each outcome based on historical data sets and real-time variables.

Usage: Often used with 'of' followed by a gerund or noun phrase.

### 3. a likely event

noun · CEFR C1 · Formal

something that is very likely to happen.

For teachers: a probable event or outcome; something that can reasonably be expected to occur.

- A change in the law is now a strong probability rather than just a hope.
- While a total market collapse is unlikely, a period of stagnation is a distinct probability that investors must prepare for.

## Examples

- There is a high probability of rain this afternoon.
- The doctor explained that the probability of a full recovery was high if the patient followed the treatment plan.
- While the individual outcomes of a coin toss are random, the mathematical probability of landing on heads remains exactly fifty percent over a sufficiently large number of trials.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.