What is "cumulant"

n. (context mathematics English) Any of a set of parameters of a one-dimensional probability distribution of a certain form

In probability theory and statistics, the cumulants of a probability distribution are a set of quantities that provide an alternative to the moments of the distribution. The moments determine the cumulants in the sense that any two probability distributions whose moments are identical will have identical cumulants as well, and similarly the cumulants determine the moments. In some cases theoretical treatments of problems in terms of cumulants are simpler than those using moments.

Just as for moments, where joint moments are used for collections of random variables, it is possible to define joint cumulants.