(mathematics) A function of one or more independent variables, at least one of which is itself a function of one or more other independent variables; a function of function(s).

(computing) Any function that is provided as part of a high-level language and can be executed by a simple reference with specification of arguments

(mathematics) A function whose value is always the same as its independent variable, and for which the codomain equals the domain.

(mathematics) Any function that is a solution of the hypergeometric equation; usually an expansion of an hypergeometric series

(mathematics) Any function that possesses a finite integral

(computing) A function used in an operating system that is not available to application programs.

(mathematics) A function that assigns a pair of vertices to each edge of a graph.

(mathematics) Any generalized function which is defined by its behavior under integration.

(mathematics) Any function whose range is n-dimensional

(mathematics) Any function of a real variable whose value increases (or is constant) as the variable increases.