probability

[ prob-uh-bil-i-tee ]

noun

, plural prob·a·bil·i·ties.

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.
   1. 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.
   2. the relative frequency with which an event occurs or is likely to occur.

probability

/ ˌprɒbəˈbɪlɪtɪ /

noun

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 )

probability

/ prŏb′ə-bĭl′ĭ-tē /

1. 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 .

probability

1. 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.

Other Words From

• nonprob·a·bili·ty noun plural nonprobabilities
• super·proba·bili·ty noun plural superprobabilities

Word History and Origins

Origin of probability¹

From the Latin word probābilitās, dating back to 1545–55. See probable, -ity

Idioms and Phrases

Idioms

1. in all probability, very probably; quite likely:

   The factory will in all probability be relocated.

More idioms and phrases containing probability

see in all probability .

Example Sentences

Trump has promised to pardon the Jan. 6 convicts; in all probability, the Jan. 6 convicts will repay Trump with their absolute loyalty as they take on the role of being his personal enforcers.

From Salon

Meanwhile, patients with amyloid values of less than 5.5 in their CSF predominantly had PET scans that showed up as abnormal as well -- meaning they tested positive for Alzheimer's with a high degree of probability.

From Science Daily

In a criminal case, the burden of proof is beyond reasonable doubt, while in a civil case, it is on the balance of probabilities.

From BBC

Acute kidney failure, severe preeclampsia and blood clotting were also associated with a lower probability of a second pregnancy.

From Science Daily

Results showed an enormous difference -- more than 70 percentage points -- in the probability between these two groups that respondents would strongly agree that sports build character.

From Science Daily

Related Words

• anticipation
• chance
• contingency
• expectation
• feasibility
• odds
• possibility
• prospect