# probability

noun prob·a·bil·i·ty \ ˌprä-bə-ˈbi-lə-tē \
Updated on: 9 Jan 2018

## Definition of probability

plural probabilities
1 : the quality or state of being probable
2 : something (such as an event or circumstance) that is probable
3 a (1) : the ratio of the number of outcomes in an exhaustive set of equally likely outcomes that produce a given event to the total number of possible outcomes
(2) : the chance that a given event will occur
b : a branch of mathematics concerned with the study of probabilities
4 : a logical relation between statements such that evidence confirming one confirms the other to some degree

## Examples of probability in a Sentence

1. There is a low probability that you will be chosen.

2. There is some probability of rain tomorrow.

3. With the dark clouds moving in, rain seems more like a probability than a possibility.

4. The probability of a coin coming up heads is one out of every two tries.

## Recent Examples of probability from the Web

• The Buckeyes have a 65 percent win probability vs. Georgia in the simulations compared to only 40 percent vs. Alabama.
• Specifics are hard, but sleuths and analysts have a somewhat good idea of what's going to happen in 2018 based on trends and probabilities.
• In the L’Aquila earthquake in Italy in 2009 (a low-probability event with high stakes, much like an eruption), more than 300 people died.
• But now there is a greater probability courts could void such agreements deeming them against the public interest.
• Max Born’s Nobel Prize Born won a Nobel Prize in 1954 along with Walther Bothe for their work on a theory that uses probability to predict the location of wave particles.
• This probability assessment is largely based on the transfer speeds of megabytes of DNC data.
• To a long-suffering merchant dealing with shoplifting or a couple suddenly bereft of their car, numbers and probabilities don't matter.
• Instead, the agency addresses overall conditions in a probability scale.

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'probability.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

15th century

## probability Synonyms

###### Synonyms
liability, likelihood
###### Antonyms
improbability, unlikelihood, unlikeliness
###### Related Words
credibility, plausibility, plausibleness; feasibility, feasibleness, possibility, potentiality, reasonability, reasonableness, viability
###### Near Antonyms
doubtfulness, dubiousness; impracticability, impracticality; implausibility, incredibility, incredibleness

noun

## Definition of probability for English Language Learners

• : the chance that something will happen

• : something that has a chance of happening

• : a measure of how often a particular event will happen if something (such as tossing a coin) is done repeatedly

## probability

noun prob·a·bil·i·ty \ ˌprä-bə-ˈbi-lə-tē \

## Definition of probability for Students

plural probabilities
1 : the chance of happening
• The probability of rain is low.
2 : something likely
• Rain is a probability.
3 : a measure of how likely a given event is
• The probability of a coin landing face up is ¹/₂.

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