functional

American  

[fuhngk-shuh-nl] / ˈfʌŋk ʃə nl /

adjective

1. of or relating to a function or functions.

   functional difficulties in the administration.

2. capable of operating or functioning.

   When will the ventilating system be functional again?

3. having or serving a utilitarian purpose; capable of serving the purpose for which it was designed.

   functional architecture; a chair that is functional as well as decorative.

4. Also functionalistic (of a building or furnishing) constructed or made according to the principles of functionalism or primarily as a direct fulfillment of a material need.

5. Medicine/Medical. without a known organic cause or structural change.

   a functional disorder.

6. pertaining to an algebraic operation.

   a functional symbol.

7. Linguistics. (of linguistic analysis, language teaching, etc.) concerned with the communicative role of language rather than, in addition to, or as the framework for its formal structure.

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noun

1. Mathematics. a function that has a domain whose elements are functions, sets, or the like, and that assumes numerical values.

functional British  

/ ˈfʌŋkʃənəl /

adjective

1. of, involving, or containing a function or functions

2. practical rather than decorative; utilitarian

   functional architecture

3. capable of functioning; working

4. med affecting a function of an organ without structural change

5. psychol

   1. relating to the purpose or context of a behaviour

   2. denoting a psychosis such as schizophrenia assumed not to have a direct organic cause, like deterioration or poisoning of the brain Compare organic psychosis

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noun

1. maths a function whose domain is a set of functions and whose range is a set of functions or a set of numbers

Other Word Forms

• functionality
  noun
• hyperfunctional
  adjective
• multifunctional
  adjective
• nonfunctional
  adjective
• prefunctional
  adjective
• semifunctional
  adjective
• subfunctional
  adjective
• superfunctional
  adjective
• unfunctional
  adjective
• functionally
  adverb
• hyperfunctionally
  adverb
• nonfunctionally
  adverb
• semifunctionally
  adverb
• subfunctionally
  adverb
• unfunctionally
  adverb

Etymology

Origin of functional

First recorded in 1625–35; function + -al ¹

Explanation

Use the adjective functional to describe something that is made to do a specific job, such as the functional alarm clock feature on a digital stopwatch. The word functional comes from the Latin word functionem, meaning "performance, execution." It can also describe whether something is working properly. This is what shoppers at a garage sale want to be sure of before they leave with an old television — they plug it in to make sure it's functional. In this case the opposite of functional is useless.

Example Sentences

See Examples For:

functional

This is where you really need to have a handle on your functional budgeting in retirement.

From MarketWatch ● Aug. 19, 2026

The effects of cortisol were also visible in the functional MRI data.

From Science Daily ● Aug. 9, 2026

“Mechanics, functional strength, nutrition, sleep, recovery, mental focus—it was all part of the equation.”

From The Wall Street Journal ● Aug. 7, 2026

In the third, an unreleased research AI model, couldn’t find the functional target company and looked for alternatives, scanning 9,000 targets on the internet and eventually finding one.

From Los Angeles Times ● Aug. 1, 2026

When I head outside, I'll confirm Pathfinder's still functional before moving on to the sweaty, annoying work of the day.

From "The Martian" by Andy Weir

Related Words

• practical
• useful
• utilitarian