function

American  

[fuhngk-shuhn] / ˈfʌŋk ʃən /

noun

• functions
  plural

1. the kind of action or activity proper to a person, thing, or institution; the purpose for which something is designed or exists; role.

2. any ceremonious public or social gathering or occasion.

3. a factor related to or dependent upon other factors.

   Price is a function of supply and demand.

4. Mathematics.

   1. Also called correspondence, map, mapping, transformation.  a relation between two sets in which one element of the second set is assigned to each element of the first set, as the expression y = x 2 ; operator.

   2. Also called multiple-value function.  a relation between two sets in which two or more elements of the second set are assigned to each element of the first set, as y 2 = x 2 , which assigns to every x the two values y = + x and y = − x.

   3. a set of ordered pairs in which none of the first elements of the pairs appears twice.

   4. a relationship in which an input value of a variable has a specifically calculated output value: for example, if the function of x is x 2 , the output will always be the square of whatever the value of x is. f, F

5. Geometry.

   1. a formula expressing a relation between the angles of a triangle and its sides, as sine or cosine.

   2. hyperbolic function.

6. Grammar.

   1. the grammatical role a linguistic form has or the position it occupies in a particular construction.

   2. the grammatical roles or the positions of a linguistic form or form class collectively.

7. Sociology. the contribution made by a sociocultural phenomenon to an ongoing social system.

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verb (used without object)

• functions,
  present (3rd person singular)
• functioned,
  past participle,  past
• functioning
  present participle

1. to perform a specified action or activity; work; operate.

   The computer isn't functioning now. He rarely functions before noon.

2. to have or exercise a function; serve.

   In earlier English the present tense often functioned as a future. This orange crate can function as a chair.

function British  

/ ˈfʌŋkʃən /

noun

1. the natural action or intended purpose of a person or thing in a specific role

   the function of a hammer is to hit nails into wood

2. an official or formal social gathering or ceremony

3. a factor dependent upon another or other factors

   the length of the flight is a function of the weather

4. Also called: map.   mapping.  maths logic a relation between two sets that associates a unique element (the value) of the second (the range) with each element (the argument) of the first (the domain): a many-one relation. Symbol: f( x ) The value of f( x ) for x = 2 is f(2)

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verb

1. to operate or perform as specified; work properly

2. (foll by as) to perform the action or role (of something or someone else)

   a coin may function as a screwdriver

function Scientific  

/ fŭngk′shən /

1. A relationship between two sets that matches each member of the first set with a unique member of the second set. Functions are often expressed as an equation, such as y = x + 5, meaning that y is a function of x such that for any value of x, the value of y will be 5 greater than x.

2. A quantity whose value depends on the value given to one or more related quantities. For example, the area of a square is a function of the length of its sides.

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function Cultural  

1. In mathematics, a quantity whose value is determined by the value of some other quantity. For example, “The yield of this field is a function of the amount of fertilizer applied” means that a given amount of fertilizer will yield an amount of whatever crop is growing.

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Other Word Forms

Derived Forms

• prefunction
  noun
• subfunction
  noun
• superfunction
  noun
• refunction
  verb (used without object)
• functionless
  adjective
• interfunction
  adjective
• multifunction
  adjective
• nonfunctioning
  adjective
• overfunctioning
  adjective
• unfunctioning
  adjective
• well-functioning
  adjective

Inflected Forms

Nouns

• functions
  plural

Participles

• functioning
  present
• functioned
  past

Conjugated Forms

Present

• function
  simple
• functions
  simple
• have functioned
  perfect
• has functioned
  perfect
• am functioning
  progressive
• are functioning
  progressive
• is functioning
  progressive
• have been functioning
  perfect progressive
• has been functioning
  perfect progressive

Past

• functioned
  simple
• had functioned
  perfect
• was functioning
  progressive
• were functioning
  progressive
• had been functioning
  perfect progressive

Future

• will function
  simple
• will have functioned
  perfect
• will be functioning
  progressive
• will have been functioning
  perfect progressive

Etymology

Origin of function

First recorded in 1525–35; from Latin functiōn- (stem of functiō ) “a performance, execution,” equivalent to funct(us) (past participle of fungī ) “performed, executed” + -iōn- -ion

Explanation

In the old "Schoolhouse Rock" song, "Conjunction junction, what's your function?," the word function means, "What does a conjunction do?" The famous design dictum "form follows function" tells us that an object's design should reflect what it does. Function is one of those words that gets used a lot and means lots of different things. It means what something does, but also what a person does, whether something or someone is doing what they should, and crazily enough, a big party. "Your function is to bring the senator coffee at the political function. He cannot function without it."

Example Sentences

See Examples For:

function functions functioned functioning

This preliminary study is the first to examine how vitamin D supplement intake relates to cognitive function specifically in a high-risk group experiencing both MCI and sleep disturbances.

From Science Daily ● Aug. 23, 2026

Growing evidence also points to a possible role for the gut microbiome in controlling muscle mass and function.

From Science Daily ● Aug. 22, 2026

After a struggle to find suitable hospital beds, he has now had device called a Berlin Heart, external fitted, which takes over the function of his heart.

From BBC ● Aug. 22, 2026

I was still fiddling with the controls when I inadvertently engaged FSD’s route-following function.

From The Wall Street Journal ● Aug. 22, 2026

Blending inheritance would function as his natural genetic prison: even if he mated—precisely when he mated—his hereditary features would instantly vanish into a sea of normalcy.

From "The Gene" by Siddhartha Mukherjee

He functions as a deep-lying conductor and would complement Anderson, who is comfortable as a box-to-box midfielder as well as the number six role he plays for England.

From BBC ● Aug. 23, 2026

Chinese regulators have pushed back on screen-only controls for certain safety-related vehicle functions, such as windows and doors.

From The Wall Street Journal ● Aug. 22, 2026

“There will be some changes in functions in terms of what people do,” Winfrey said.

From Los Angeles Times ● Aug. 20, 2026

As Puck’s Leigh Ann Caldwell recently observed, he is seen as quiet and studious in the Senate, someone who rarely attends Washington social functions, who is professorial by nature.

From Salon ● Aug. 20, 2026

I went on missions to inspect fallen trees that needed removing, talked to neighborhood pastors who were upset about traffic or garbage collection, and often represented the mayor’s office at community functions.

From "Becoming" by Michelle Obama

Rather than serving as a heavy hammer, it functioned as a softer striking tool used to repair and sharpen stone handaxes and other cutting implements after their edges became worn.

From Science Daily ● Jul. 27, 2026

Married to the legendary Washington Post editor Ben Bradlee until his death in 2014, Quinn has functioned, at least since the 1980s, as the self-appointed spokeswoman of the nation’s permanent political establishment.

From Salon ● Jul. 21, 2026

In another lawsuit, he claimed an arcade rigged its claw machines against players, alleging it functioned as “a casino for children.”

From Los Angeles Times ● Jul. 8, 2026

If the company insists that this is a separate problem, ask them to explain why a toilet that functioned one way before the repair and another way immediately afterward should attract a second diagnostic fee.

From MarketWatch ● Jun. 10, 2026

Archaide was both a PvP zone and a chaos zone, which meant that both magic and technology functioned here.

From "Ready Player One: A Novel" by Ernest Cline

They added: “We can find nothing in market functioning that would force Treasury to increase long-end buybacks at this moment,” they said.

From MarketWatch ● Aug. 20, 2026

Though it was presented as a technical maneuver to improve the smooth functioning of the bond market, many on Wall Street saw the buyback plan as an obvious effort to achieve Bessent’s previously stated aims.

From The Wall Street Journal ● Aug. 19, 2026

That ability to keep functioning while transporting larger bacterial clusters points to possible future uses in microbiology, biomedical research, and precise manipulation of materials at the microscopic scale.

From Science Daily ● Aug. 18, 2026

He taped the unfeeling fingers to the functioning ones so that he could grip a baseball, then, resembling “a little boy throwing against the steps of his back porch,” threw against a wall.

From Los Angeles Times ● Aug. 16, 2026

And, in one cage, a no longer functioning false animal, a chicken.

From "Do Androids Dream of Electric Sheep?" by Philip K. Dick

Related Words

• action
• activity
• affair
• behavior
• business
• duty
• exercise
• objective
• operation
• part
• power
• purpose
• responsibility
• role
• service
• situation
• task
• work