parameter

American  

[puh-ram-i-ter] / pəˈræm ɪ tər /

noun

1. Mathematics.

   1. a constant or variable term in a function that determines the specific form of the function but not its general nature, as a in f (x ) = ax, where a determines only the slope of the line described by f (x ).

   2. one of the independent variables in a set of parametric equations.

2. Statistics. a variable entering into the mathematical form of any distribution such that the possible values of the variable correspond to different distributions.

3. Computers. a variable that must be given a specific value during the execution of a program or of a procedure within a program.

4. Usually parameters. limits or boundaries; guidelines.

   the basic parameters of our foreign policy.

5. characteristic or factor; aspect; element.

   a useful parameter for judging long-term success.

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parameter British  

/ pəˈræmɪtə, ˌpærəˈmɛtrɪk /

noun

1. one of a number of auxiliary variables in terms of which all the variables in an implicit functional relationship can be explicitly expressed See parametric equations

2. a variable whose behaviour is not being considered and which may for present purposes be regarded as a constant, as y in the partial derivative ∂f( x,y )/∂ x

3. statistics a characteristic of the distribution of a population, such as its mean, as distinct from that of a sample Compare statistic

4. informal any constant or limiting factor

   a designer must work within the parameters of budget and practicality

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parameter Cultural  

1. A quantity or number on which some other quantity or number depends. An informal example is, “Depending on the traffic, it takes me between twenty minutes and an hour to drive to work”; here, “traffic” is the parameter that determines the time it takes to get to work. In statistics, a parameter is an unknown characteristic of a population — for example, the number of women in a particular precinct who will vote Democratic.

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Usage

Some object strongly to the use of parameter in these newer senses. Nevertheless, the criticized uses are now well established both in educated speech and in edited writing.

Discover More

The term is often mistakenly used to refer to the limits of possible values a variable can have because of confusion with the word perimeter.

Other Word Forms

• parametric adjective
• parametrical adjective

Etymology

Origin of parameter

From the New Latin word parametrum, dating back to 1650–60; para- ¹, -meter

Explanation

A parameter is a limit. In mathematics a parameter is a constant in an equation, but parameter isn’t just for math anymore: now any system can have parameters that define its operation. You can set parameters for your class debate. Parameter comes from a combination of the Greek word para-, meaning “beside,” and metron, meaning “measure.” The natural world sets certain parameters, like gravity and time. In court, the law defines the parameters of legal behavior. Parameter and perimeter are similar, but a perimeter is the physical distance around an object, while a parameter can contain or define something either physically or abstractly.

Example Sentences

Bonsai 8B is an 8-billion parameter large language model, trained using Google v4 TPUs.

From The Wall Street Journal • Mar. 31, 2026

"This would require moving away from simply using caste as the parameter for redistribution of available resources, to use of both caste and income levels in policymaking."

From BBC • Nov. 12, 2025

Each time he adjusted even a single parameter, it could take days of extra computation to see the results.

From Science Daily • Oct. 30, 2025

Data from this parameter would be important to examine, said UC Berkeley emeritus professor of education Bruce Fuller.

From Los Angeles Times • Jul. 22, 2025

Reluctantly, he acquiesced; the test showed that he suffered from elevated levels of serum creatinine with a value way above 1.4, the highest parameter in the normal range.

From "Endgame" by Frank Brady

Related Words

• criterion
• framework
• guideline
• restriction
• specification