(noun, adjective)


1. useful; serving a purpose, fulfilling a function.

- a style of writing in which every word is functional

- functional architecture

Similar word(s): structural, useful, utilitarian, serviceable

2. relating to or based on function especially as opposed to structure

- the problem now is not a constitutional one; it is a functional one

- delegates elected on a functional rather than a geographical basis

3. fit or ready for use or service

- the toaster was still functional even after being dropped

Similar word(s): serviceable, operable, operational, usable, useable

4. designed for or adapted to a function or use

- functional education selects knowledge that is usable in the real world

Similar word(s): practical

5. (of e.g. a machine) performing or capable of performing

- a functional set of brakes

Similar word(s): functioning, operative, running, working

Sentences with functional as an adjective:

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

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


1. (mathematics) 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.

2. (mathematics, functional analysis) A scalar-valued linear function on a vector space

3. (computing) An object encapsulating a function pointer (or equivalent).