Bayes' theorem

noun

ˈbāz- 

variants or less commonly Bayes theorem or less commonly Bayes's theorem

: a theorem about conditional probabilities: the probability that an event A occurs given that another event B has already occurred is equal to the probability that the event B occurs given that A has already occurred multiplied by the probability of occurrence of event A and divided by the probability of occurrence of event B

Word History

Etymology

Thomas Bayes †1761 English mathematician

First Known Use

1830, in the meaning defined above