function meaning

• Noun: function  fúngkshun
  1. (mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function)
     - mathematical function, single-valued function, map, mapping 
  2. What something is used for
     "the function of an auger is to bore holes"
     - purpose, role, use 
  3. The actions and activities assigned to or required or expected of a person or group
     "the function of a teacher"
     - office, part, role 
  4. A relation such that one thing is dependent on another
     "height is a function of age"; "price is a function of supply and demand" 
  5. A formal or official social gathering or ceremony
     "it was a black-tie function" 
  6. A vaguely specified social event
     "a seemingly endless round of social functions"
     - affair, occasion, social occasion, social function 
  7. A set sequence of steps, part of larger computer program
     - routine, subroutine, subprogram, procedure
  Verb: function  fúngkshun
  1. Perform as expected when applied
     - work, operate, go, run 
  2. Serve a purpose, role, or function
     "The table functions as a desk"
     - serve 
  3. Perform duties attached to a particular office or place or function
     - officiate

  Derived forms: functions, functioning, functioned

  See also: functional, functionary, functioning, nonfunctional

  Type of: answer, computer software, do, duty, mathematical relation, package, relation, serve, social affair, social event, social gathering, software, software package, software program, software system, suffice, usefulness, utility

  Antonym: malfunction

  Part of: computer program, computer programme [Brit], program, programme [Brit, Cdn]

  Encyclopedia: Function

• 
  [Business]
  noun, verb

  ■ noun

  CONSUMPTION FUNCTION

  1 [C,U]

  a special activity or purpose of a person or thing:

  to fulfil/perform a useful function

  Smartphones combine the functions of cell phones and handheld computers.

  Your function is to run your department efficiently.

  2 [C]

  the part of a company that is responsible for a particular area:

  accounting, manufacturing, sales and marketing and other corporate functions

  We considered splitting up our key business functions so that they were not all in one place.

  3 (IT ) [C]

  a part of a program, etc. that carries out a basic operation:

  the function keys

  4 [C]

  a social event or official ceremony:

  The staff are allowed two social functions a year.

  The hall provides a venue for weddings and other functions.

  5 [sing.] a function of sth

  if one thing is a function of another, its value depends on the varying values of the other thing

  : (figurative) Salary is a function of age and experience.

  He believed that success was a function of competence and hard work.

  ■ verb [no obj]

  to work in the correct way:

  The fire alarm system is now functioning again.

  a fully functioning market economy

  Small companies can't function without good teamwork.

  SYN OPERATE

  PHRASAL VERBS

  function as sb/sth

  to perform the action or the job of the thing or person mentioned:

  The sofa also functions as a bed.

  The managers had already been functioning as owners of the company.

• 
  [Economics]
  A relation between two or more variables. If y is a function of x, written y = f (x), when the value of the argument x is known, the function tells us how to find the value of y. If y is a single-valued function of x, for each value of x there is only one value of y. In the linear function y = ax + b, for example, or the quadratic function y = ax² + bx + c, y is a single-valued function of x. For some functions, however, there may be more than one value of y for any given x, or there may be no real values of y. For example, if y = √x, when x < 0 there are two values of y, since for any y such that y² = x, it is always also true that (-y)² = x. When x > 0, however, there are no real values of y, but two ‘imaginary’ numbers, iz and -iz, where z² = -x. It is also common to have a function of several variables, for example y = f (x₁, x₂, …, x_N). In this case every x_i from x₁ to x_N needs to be specified to determine y.

  See also:

  decreasing function, homogeneous function, implicit function, increasing function, inverse function, linear function, log-linear function, monotonic function, non-linear function, oscillatory function, piecewise linear function, step function, and trigonometric function

• 
  [Electronics]
  1. A mapping between two sets of quantities or points A and B, such that: (1) For each yin B, there exists at least one corresponding x in A; and (2) For each x in A, there exists exactly one y in B. In this case y is said to be a function of x; this can be written as y = f(x). The set A is called the domain of f; the set B is called the range of f.
  2. A mathematical expression, using symbols, relating variables (e.g., the expression x - y = z is a function of variables x, y, and z).
  3. The behavior and application for which a device or system is designed.
  4. Part of a computer instruction specifying the operation to be done.
  

[Medicine]
n : any of a group of related actions contributing to a larger action; esp : the normal and specific contribution of a bodily part to the economy of a living organism — func·tion·less adj
vi func·tioned; func·tion·ing : to have a function ‹shivering functions to maintain the heat of the body›

• 
  [Oil and gas]
  Operation of a well control component, choke or kill valve, or any other component in one direction. For example, closing the blind rams is one function and opening the blind rams is a separate function.
• 
  [Computer]
  1. <mathematics> (Or "map", "mapping") If D and C are sets (the domain and codomain) then a function f from D to C, normally written "f : D -> C" is a subset of D x C such that:
  
  1. For each d in D there exists some c in C such that (d,c) is an element of f. I.e. the function is defined for every element of D.
  
  2. For each d in D, c1 and c2 in C, if both (d,c1) and (d,c2) are elements of f then c1 = c2. I.e. the function is uniquely defined for every element of D.
  
  See also image, inverse, partial function.
  
  2. <programming> Computing usage derives from the mathematical term but is much less strict. In programming (except in functional programming), a function may return different values each time it is called with the same argument values and may have side effects.
  
  A procedure is a function which returns no value but has only side-effects. The C language, for example, has no procedures, only functions. ANSI C even defines a type, void, for the result of a function that has no result.

• function as:    function as sth to ...
• function / functionary | function | functionary |:    [Law]FUNCTION - Th ...
• aperiodic function:    [Electronics]A non ...

Examples

1. insects' horns have various functions.
2. the function is rather badly behaved.
3. travel was a function of national wealth.
4. congress has assumed some negative functions.
5. some english adverbs function as adjectives.