# probability

[ prob-uh-bil-i-tee ]

/ ˌprɒb əˈbɪl ɪ ti /

### noun, plural prob·a·bil·i·ties.

the quality or fact of being probable.

a strong likelihood or chance of something: The probability of the book's success makes us optimistic.

a probable event, circumstance, etc.: Our going to China is a probability.

Statistics.

- the relative possibility that an event will occur, as expressed by the ratio of the number of actual occurrences to the total number of possible occurrences.
- the relative frequency with which an event occurs or is likely to occur.

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What Is The Difference Between “Might” And “May”?May expresses likelihood while might expresses a stronger sense of doubt or a contrary-to-fact hypothetical. The difference in degree between “You may be right” and “You might be right” is slight but not insignificant: if I say you may be right about something, there is a higher degree of probability that you are right about it than if I say you might be right about something. Example: You think Einstein is the most brilliant physicist who …

## RELATED WORDS

## Nearby words

### Idioms

in all probability, very probably; quite likely: The factory will in all probability be relocated.

Related formsnon·prob·a·bil·i·ty, noun, plural non·prob·a·bil·i·ties.su·per·prob·a·bil·i·ty, noun, plural su·per·prob·a·bil·i·ties.

Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

## Examples from the Web for probability

## British Dictionary definitions for probability

## probability

/ (ˌprɒbəˈbɪlɪtɪ) /

### noun plural -ties

the condition of being probable

an event or other thing that is probable

statistics a measure or estimate of the degree of confidence one may have in the occurrence of an event, measured on a scale from zero (impossibility) to one (certainty). It may be defined as the proportion of favourable outcomes to the total number of possibilities if these are indifferent (mathematical probability), or the proportion observed in a sample (empirical probability), or the limit of this as the sample size tends to infinity (relative frequency), or by more subjective criteria (subjective probability)

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

## Word Origin and History for probability

## probability

mid-15c., "quality of being probable," from Old French probabilite (14c.) and directly from Latin probabilitatem (nominative probabilitas) "credibility, probability," from probabilis (see probable). Meaning "something likely to be true" is from 1570s; mathematical sense is from 1718.

Online Etymology Dictionary, © 2010 Douglas Harper

## Science definitions for probability

## probability

[ prŏb′ə-bĭl′ĭ-tē ]

A number expressing the likelihood of the occurrence of a given event, especially a fraction expressing how many times the event will happen in a given number of tests or experiments. For example, when rolling a six-sided die, the probability of rolling a particular side is 1 in 6, or 16.

The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

## Culture definitions for probability

## probability

A number between zero and one that shows how likely a certain event is. Usually, probability is expressed as a ratio: the number of experimental results that would produce the event divided by the number of experimental results considered possible. Thus, the probability of drawing the ten of clubs from an ordinary deck of cards is one in fifty-two (1:52), or one fifty-second.

The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

## Idioms and Phrases with probability

## probability

see in all probability.

The American Heritage® Idioms Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.