functional

A function that takes a function as its argument; More precisely: A function y=f(x) whose argument x varies in a space of (real valued, complex valued) functions and whose value belongs to a monodimensional space. An example: the definite integration of integrable real functions in a real interval.

A scalar-valued linear function on a vector space.

An object encapsulating a function pointer (or equivalent).

In good working order.

Useful; serving a purpose, fulfilling a function

“That sculpture is not merely artistic, but also functional: it can be used as a hatrack.”

Only for functional purposes, notably in architecture

“A functional construction element generally must meet higher technical but lower aesthetical requirements”

Having semantics defined purely in terms of mathematical functions, without side-effects.

Of a disease, such that its symptoms cannot be referred to any appreciable lesion or change of structure; opposed to organic disease, in which the organ itself is affected.