Wiktionary
n. 1 (context mathematics computing English) A function whose value is chosen at random from its domain 2 (context mathematics English) A function chosen at random from a set of functions
Wikipedia
In probability theory and its applications, such as statistics and cryptography, a random function is a function chosen randomly from a family of possible functions. Each realisation of a random function would result in a different function. Thus the concept of a random function is one example of a random element and hence is a generalization of the simpler idea of a random variable.
In probability and statistics, one important type of random function is studied under the name of stochastic processes, for which there are a variety of models describing systems where an observation is a random function of time or space. However, there are other applications where there is a need to describe the uncertainty with which a function is known and where the state of knowledge about the true function can be expressed by saying that it is an unknown realisation of a random function, for example in the Dirichlet process.
A special case of a random function is a random permutation, where a realisation can be interpreted as being in the form of a function on the set of integers describing the original location of an item, where the value of the function provides the new (permuted) location of the item that was in a given location.
In cryptography, a random function can be a useful building block in enabling cryptographic protocols.
Usage examples of "random function".
Perhaps a pseudo-random function of the date, perhaps random numbers you are taking from a one-time pad.
He's got the logical function underneath and the random function on top.
We found early on that using the same face and body for many androids was maddening when it came to finding a particular one, so we programmed a random function into our construction computers.