function

American  

[fuhngk-shuhn] / ˈfʌŋk ʃən /

noun

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)

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

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

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

These agents, created from Gemini or another AI model, function by constantly inferencing—or accessing—AI computing.

From Barron's • May 14, 2026

Three managers - Carlo Ancelotti, Xabi Alonso, Arbeloa - have been unable to make them function as a partnership.

From BBC • May 13, 2026

They function much the same way as surrogacy contracts, which similarly establish legal parentage through contract rather than biology.

From Slate • May 13, 2026

Researchers also noted that speech provides valuable insight into processing speed and overall cognitive function in real-world situations, without requiring strict time limits that are common in many traditional cognitive assessments.

From Science Daily • May 13, 2026

The rule provided a way to figure out the true value of a mathematical function that goes to 0/0 at a point.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

Related Words

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