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

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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

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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

ME has no known cure or specific treatment, with patients often relying on off-label medication to manage a condition that can cause more than 200 symptoms, including nausea, headaches, poor cognitive function and brain fog.

From BBC ● Oct. 16, 2026

Changing its levels directly affected muscle function, strengthening the case that it plays an important role in the aging process.

From Science Daily ● Oct. 16, 2026

California Secretary of State Shirley Weber said the federal list of names lacks the detail and function to be of any investigative use.

From The Wall Street Journal ● Oct. 15, 2026

Meanwhile, pressure on U.S. 10-year treasury yields was slightly easing Thursday, which Jefferies equities trading analyst Jeffrey Favuzza said was likely “a function around the sentiment in AI.”

From MarketWatch ● Oct. 15, 2026

“We had a function at my school this afternoon. For the debate team, and I was the first speaker.”

From "Amina's Song" by Hena Khan

Mice with reduced PD-L2 activity also showed improvements in their ability to process sugar and demonstrated greater grip strength, suggesting that targeting the protein could influence physical functions affected by aging.

From Science Daily ● Oct. 14, 2026

Los Angeles County will conduct future homeless counts and apply for federal grants on behalf of the region’s homeless services providers, taking over two functions from the beleaguered Los Angeles Homeless Services Authority.

From Los Angeles Times ● Oct. 14, 2026

Moynihan said the company had redeployed some staff to fulfill compliance obligations, meaning it won't mean additional costs in the future for these functions.

From Barron's ● Oct. 14, 2026

Their experimental design relied on two different quantum components that performed separate functions.

From Science Daily ● Oct. 13, 2026

The brain stem keeps many of your automatic functions going, like your breathing and heartbeat.

From "Phineas Gage" by John Fleischman

Some tech-savvy investors built custom sets of agents that functioned like mini money managers, crunching numbers and monitoring the market like a team of analysts at a hedge fund.

From The Wall Street Journal ● Sep. 29, 2026

It functioned as a musical chairs of sorts, in which the contestants switched partners until the music was paused, and a couple was announced.

From BBC ● Sep. 19, 2026

At first, the account functioned like a group chat for local surfers.

From Los Angeles Times ● Sep. 14, 2026

Rather than serving as "an impartial chronographic work," the researchers suggest it may instead have functioned as "a legitimizing canon of kings, which was periodically updated to remove short-lived or parallel Neo-Assyrian rulers."

From Science Daily ● Aug. 26, 2026

One of the reasons the Globe was such a hip, exclusive club was because it was located in a PvP zone, one where both magic and technology functioned.

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

The inquest heard that the 24-year-old was under adult mental health services in Doncaster, but was "highly functioning and independent with no care requirements".

From BBC ● Oct. 16, 2026

Rather than standing on the verge of a functioning nuclear reactor, the German scientists faced shortages they could not overcome with the resources available to them.

From Science Daily ● Oct. 16, 2026

Such conditions, such as irritable bowel syndrome, result in gastrointestinal symptoms related to the functioning of the autonomic nervous system.

From The Wall Street Journal ● Oct. 12, 2026

SB 942 declares that detainees at state, local and privately run facilities have the right to medical, dental and mental health care; physical exercise; clean drinking water and functioning toilets; and other rights.

From Los Angeles Times ● Oct. 7, 2026

Once you join the residents in forgetting about the functioning humans they once were, you can think of them as a band of wizened toddlers at a tea party.

From "Nickel and Dimed: On (Not) Getting By in America" by Barbara Ehrenreich

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Related Words

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

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