function

Meanings

1. 1nouncountable

   The purpose or role that something is designed to have, or the way it works.

   Grammar: Often used with 'of' or 'as': the function of the heart; serve a function.

   Patterns

   • the function of something
   • serve a function
   • perform a function

   The function of the kidneys is to filter blood.

   This tool serves a specific function in the kitchen.

   The main function of the committee is to advise the board.

2. 2nouncountablemathematics

   A mathematical relationship in which each input has exactly one output.

   Grammar: Used in mathematics; often followed by 'of': f(x) is a function of x.

   Patterns

   • a function of something
   • the function f(x)
   • a linear function

   In algebra, a function assigns exactly one output to each input.

   The graph of a quadratic function is a parabola.

   We studied linear functions in math class.

3. 3verbintransitive

   To work or operate in a particular way.

   Grammar: No object; often followed by adverbs or prepositional phrases: The machine functions well.

   Patterns

   • function as something
   • function properly
   • function without something

   The elevator is not functioning properly.

   This room functions as both an office and a guest room.

   The country cannot function without a stable government.

4. 4nouncountableBritishformal

   A formal social event or gathering, often for a business or ceremonial purpose.

   Grammar: Used especially in British English for official or formal occasions.

   Patterns

   • attend a function
   • a social function
   • a charity function

   They attended a charity function at the hotel.

   The mayor spoke at a civic function.

   He hates going to formal functions.

Word forms

Common combinations

bodily function

The disease affects normal bodily functions.

function key

Press the function key to refresh the screen.

search function

The website's search function is very fast.

function properly

The heater isn't functioning properly.

function as

The sofa functions as a bed.

Synonyms and how they differ

purpose

Purpose is the reason something exists or is done; function is the specific role or action it performs.

role

Role often refers to a person's part in a group or situation; function is more about how something works.

operate

Operate is a verb meaning to work or control a machine; function is more general and often intransitive.

Opposites

Word family

functional adjective

Designed to be practical and useful rather than attractive.

functionality noun

The range of functions that a system or product can perform.

functionally adverb

In a way that relates to how something works.

Commonly confused: function or faction?

Practice

Make it your own

Write a sentence using “function”, then check it and compare it with the examples above.

Explore more words