probability

noun

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

plural probabilities

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

• liability
• likelihood

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

After the market saw the CPI for June fall 0.1% month over month, the prospects of two or more cuts became more likely and the market now sees a roughly 50% probability of three cuts by the end of the year, according to CME FedWatch. —Jeff Marks, CNBC, 11 July 2024

Some could bring only fear, and the probability of future fear was dependent on the probability of past fear, as well as on the parent’s over-all chance of penitence. —Weike Wang, The New Yorker, 11 July 2024

Legal expert Louis Shapiro, a defense attorney not involved in the case, said to be admissible in California, a confirmatory DNA test is required to show the probability that the results are reliable. —Richard Winton, Los Angeles Times, 10 July 2024

The Colorado State report also details the probabilities of at least one major hurricane landfall in different regions after July 8. —Bill Kearney, Sun Sentinel, 9 July 2024

Word History

First Known Use

15th century, in the meaning defined at sense 3

Phrases Containing probability

• conditional probability
• in all probability
• probability density
• probability density function
• probability distribution
• probability function

Kids Definition

probability

noun

prob·​a·​bil·​i·​ty ˌpräb-ə-ˈbil-ət-ē 

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