probability Meaning, Definition & Usage

noun a measure of how likely it is that some event will occur; a number expressing the ratio of favorable cases to the whole number of cases possible
chance.
- the probability that an unbiased coin will fall with the head up is 0.5
noun the quality of being probable; a probable event or the most probable event
- for a while mutiny seemed a probability
- going by past experience there was a high probability that the visitors were lost

L. probabilitas: cf. F. probabilité.

plural Probabilities

The quality or state of being probable; appearance of reality or truth; reasonable ground of presumption; likelihood.
Probability is the appearance of the agreement or disagreement of two ideas, by the intervention of proofs whose connection is not constant, but appears for the most part to be so. Locke.
That which is or appears probable; anything that has the appearance of reality or truth.
The whole life of man is a perpetual comparison of evidence and balancing of probabilities. Buckminster.

We do not call for evidence till antecedent probabilities fail. J. H. Newman.
(Math.) Likelihood of the occurrence of any event in the doctrine of chances, or the ratio of the number of favorable chances to the whole number of chances, favorable and unfavorable. See 1st Chance, n., 5. Syn. -- Likeliness; credibleness; likelihood; chance.