probability

noun

plural probabilities
Synonyms of probability
1
a(1)
: the chance that a given event will occur
(2)
: 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
b
: a branch of mathematics concerned with the study of probabilities
2
: something (such as an event or circumstance) that is probable
3
: the quality or state of being probable
4
: a logical relation between statements such that evidence confirming one confirms the other to some degree

Synonyms of probability

Examples of probability in a Sentence

There is a low probability that you will be chosen. There is some probability of rain tomorrow. With the dark clouds moving in, rain seems more like a probability than a possibility. The probability of a coin coming up heads is one out of every two tries.
Recent Examples on the Web
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Markets exist for the supply and demand of commodities today on the basis of forecasts, estimates, and probabilities. Finn Brunton, Harpers Magazine, 1 Sep. 2026 Switch in expectations The sum of his remarks caused a sharp repricing in hike probabilities. Jeff Cox, CNBC, 31 Aug. 2026 The answer depends on the probability that your coin lands on heads, which can range from 0% to 100%. Leila Sloman, Quanta Magazine, 31 Aug. 2026 In one simulation, the AI initially assigned a 72% probability that a nearby vessel was simply passing through. Bojan Stojkovski, Interesting Engineering, 30 Aug. 2026 See All Example Sentences for probability

Word History

First Known Use

15th century, in the meaning defined at sense 3

Time Traveler
The first known use of probability was in the 15th century

Browse Nearby Words

Cite this Entry

“Probability.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/probability. Accessed 4 Sep. 2026.

Kids Definition

probability

noun
plural probabilities
1
: the quality or state of being probable
2
: something probable
3
a
: a measure of how often a particular event will happen if something which results in any of a number of possible events is done repeatedly
the probability of a coin coming up heads is ½
b
: a branch of mathematics concerned with the study of probabilities

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