pa·​ram·​e·​ter | \ pə-ˈra-mə-tər How to pronounce parameter (audio) \

Definition of parameter

1a : an arbitrary constant whose value characterizes a member of a system (such as a family of curves) also : a quantity (such as a mean or variance) that describes a statistical population
b : an independent variable used to express the coordinates of a variable point and functions of them — compare parametric equation
2 : any of a set of physical properties whose values determine the characteristics or behavior of something parameters of the atmosphere such as temperature, pressure, and density
3 : something represented by a parameter : a characteristic element broadly : characteristic, element, factor political dissent as a parameter of modern life health care is a universal parameter, … a ubiquitous concern across every age, occupation, and class line. — Wayne Biddle
4 : limit, boundary usually used in plural the parameters of science fictionThe investigation stayed within the parameters set by the court.

Other Words from parameter

parametric \ ˌper-​ə-​ˈme-​trik How to pronounce parameter (audio) , ˌpa-​rə-​ \ adjective
parametrically \ ˌper-​ə-​ˈme-​tri-​k(ə-​)lē How to pronounce parameter (audio) , ˌpa-​rə-​ \ adverb

Parameter vs. Perimeter

It's very easy to confuse parameter with perimeter. Not only do the two words sound the same, they both connote a boundary or limit.

When parameter is used to mean "a boundary or limit," it is usually in its plural form, and often as the object of a preposition such as within or beyond:

Let's face it, managing weight loss or maintenance can be trying enough within the parameters of a daily routine.
Geoff Kerr, Weight Watchers, November 1991

Though candor sometimes encourages Bruno to "stray beyond the parameters of good taste," his interaction with Lydia is always convincingly portrayed as a loving, tender relationship.
Ron Charles, The Washington Post, 8 Feb. 2011

In geometry, perimeter refers to the boundary of a closed plane figure. You might remember calculating perimeters in school. If each side of an equilateral triangle measures 9 feet, then the perimeter of the triangle measures 27 feet. In more general use, perimeter describes an outer stretch, as in "The college president lived in a house on the perimeter of the campus."

Parameter originally had a meaning pertaining to mathematics as well. The dictionary defines it as "an arbitrary constant whose value characterizes a member of a system (as a family of curves); also : a quantity (as a mean or variance) that describes a statistical population" as well as "an independent variable used to express the coordinates of a variable point and functions of them."

Some twentieth-century usage commentators objected to the use of a scientific-sounding word like parameter in general contexts (as in the examples above), especially to mean "a limit or boundary," theorizing that perimeter must have been what the speaker or writer intended.

However, perimeter was not often used in the phrasings that parameter is used in (that is, as the object of within or beyond) until much later. In fact, a word such as bounds or range or confines often serves as a more appropriate equivalent for parameter than the marginal connotations of perimeter:

But a true novel is an extended piece of fiction: Length is clearly one of its parameters.
Anthony Burgess, The New York Times Book Review, 5 Feb. 1984

Shields will then subsume that request in the overall City operating budget that he will recommend to the City Council in mid-March, and the Council will make its final decisions on the parameters of the budget, including any tax increases or cuts, by the end of April.
Nicholas F. Benton, The Falls Church News Press, 6 Jan. 2016

Examples of parameter in a Sentence

Recent Examples on the Web An attacker can inject arbitrary commands into the mtu or the data parameter. Dan Goodin, Ars Technica, 12 May 2022 If having been occupied by another foreign nation for long periods is his parameter for losing sovereignty, then the rest of the Eastern European nations, Spain, Portugal, Ireland, India and Israel don’t qualify either. WSJ, 8 Apr. 2022 Gradient descent is the iterative process of climbing down from high values of the loss function to some minimum value, which represents good enough (or sometimes even the best possible) parameter values. Quanta Magazine, 25 Jan. 2022 Large Model Research Since released access to their 85-billion parameter GPT-3 language model, large AI models have been in the spotlight. Karl Freund, Forbes, 21 Dec. 2021 For her, any remaining biological advantages that Lia Thomas has are within a reasonable parameter. Stephen Humphries, The Christian Science Monitor, 15 Mar. 2022 Omega matter is a cosmological parameter that describes how much dark matter is in the universe. Rivka Galchen, The New Yorker, 23 Mar. 2022 Therefore, if the parameter is small, the cutoff energy must be low. Quanta Magazine, 1 Mar. 2022 The machine learning algorithm also offered an estimate of how important each weather parameter was for performance. Alex Hutchinson, Outside Online, 27 Oct. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'parameter.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of parameter

1833, in the meaning defined at sense 1a

History and Etymology for parameter

New Latin, from para- + Greek metron measure — more at measure

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Time Traveler for parameter

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The first known use of parameter was in 1833

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Last Updated

15 May 2022

Cite this Entry

“Parameter.” Dictionary, Merriam-Webster, Accessed 17 May. 2022.

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More from Merriam-Webster on parameter

Nglish: Translation of parameter for Spanish Speakers

Britannica English: Translation of parameter for Arabic Speakers Encyclopedia article about parameter


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