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

The probability of thunderstorms is 10%-20%, according to the weather service, and they’re expected in the late afternoon and evening. —Cathie Anderson, Sacramento Bee, 13 Apr. 2024

The areas with the highest probability for rain showers and possibly an isolated thunderstorm are located along and east of the U.S. 65 highway and south of the U.S. 50 highway. —Robert A. Cronkleton, Kansas City Star, 10 Apr. 2024

The first is the probability of life emerging on that planet given everything else that’s known about it. —Elise Cutts, WIRED, 7 Apr. 2024

But Network Ten and journalist Lisa Wilkinson chose to fight it using a truth defense – essentially tasking their lawyers to prove on the balance of probabilities that Lehrmann did rape Higgins. —Hilary Whiteman, CNN, 6 Apr. 2024

Researchers predicted a 42% probability in that area, up from an average of 27% in previous years. —Cara Tabachnick, CBS News, 4 Apr. 2024

According to Basketball Reference’s playoff probabilities report, the Heat entered Monday with a 39.1 percent chance of finishing with a top-six seed in the East to make the playoffs without needing to take part in the play-in tournament. —Anthony Chiang, Miami Herald, 1 Apr. 2024

Because the 2024 eclipse is happening in the spring, the probability of overcast skies is greater. —Haadiza Ogwude, The Enquirer, 27 Mar. 2024

Globally, the probability one earthquake will be followed by a large earthquake within 3 days is somewhere just over 6%, according to USGS. —Elizabeth Weise, USA TODAY, 5 Apr. 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