# probability

## probability

[prob-uh-bil-i-tee]
noun, plural probabilities.
1.
the quality or fact of being probable.
2.
a strong likelihood or chance of something: The probability of the book's success makes us optimistic.
3.
a probable event, circumstance, etc.: Our going to China is a probability.
4.
Statistics.
a.
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.
b.
the relative frequency with which an event occurs or is likely to occur.
Idioms
5.
in all probability, very probably; quite likely: The factory will in all probability be relocated.

Origin:
1545–55; < Latin probābilitās. See probable, -ity

nonprobability, noun, plural nonprobabilities.
superprobability, noun, plural superprobabilities.
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
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World English Dictionary
 probability (ˌprɒbəˈbɪlɪtɪ) —n , pl -ties 1. the condition of being probable 2. an event or other thing that is probable 3. 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 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Etymonline
Word Origin & History

probability
1550s; see probable + -ity.
Online Etymology Dictionary, © 2010 Douglas Harper
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American Heritage
Science Dictionary
 probability   (prŏb'ə-bĭl'ĭ-tē)  Pronunciation Key  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 1/6 .
The American Heritage® Science Dictionary
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American Heritage
Cultural Dictionary

### probability definition

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 American Heritage® New Dictionary of Cultural Literacy, Third Edition
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American Heritage
Idioms & Phrases

probability

The American Heritage® Dictionary of Idioms by Christine Ammer.
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Encyclopedia Britannica
Encyclopedia

probability

the branches of mathematics concerned with the laws governing random events, including the collection, analysis, interpretation, and display of numerical data. Probability has its origin in the study of gambling and insurance in the 17th century, and it is now an indispensable tool of both social and natural sciences. Statistics may be said to have its origin in census counts taken thousands of years ago; as a distinct scientific discipline, however, it was developed in the early 19th century as the study of populations, economies, and moral actions and later in that century as the mathematical tool for analyzing such numbers. For technical information on these subjects, see probability theory and statistics.

Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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Example sentences
What seismologists can do is identify places where there is a high probability
of a strong earthquake happening in the future.
The probability of that happening without manipulation is one-tenth of one per
cent.
Right on target but the probability of this happening is rather low.
Still, the game probability projections continue to do well.
Idioms & Phrases
Nearby Words