# Definition of *prior probability* in English:

## prior probability

Line breaks: prior prob|abil¦ity### noun

*Statistics*

- A probability as assessed before making reference to certain relevant observations, especially subjectively or on the assumption that all possible outcomes be given the same probability.More example sentences
- The probability is either a prior probability or a conditional probability.
- The resultant posterior probability then becomes a prior probability for the second drawing, the result of which is used to calculate a further posterior probability.
- Her lawyers demonstrated that the test did not take proper account of the prior probability and thus made a tacit initial assumption of guilt.