parameter

noun pa·ram·e·ter \ pə-ˈra-mə-tər \

|Updated on: 4 Jul 2018

Editor's Note: parameter vs. perimeter

Definition of parameter

1 a : 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 fiction

The investigation stayed within the parameters set by the court.

—

parametric

play \ˌper-ə-ˈme-trik, ˌpa-rə-\ adjective

—

parametrically

play \ˌper-ə-ˈme-tri-k(ə-)lē, ˌpa-rə-\ adverb

See parameter defined for English-language learners

See parameter defined for kids

Recent Examples of parameter from the Web

This is unconventional, as typically lower-level officials with thrash out parameters in exhaustive meetings before the bigwigs swoop in for the declaration signing beneath the glare of photographers.

— Time, "Singapore's Sentosa Island Takes an Unlikely Geopolitical Role as Host of the Trump-Kim Summit," 11 June 2018
Our results recovered 12 percent more newly urbanized land area defined by the parameters determined through field survey than would have been discerned using conventional methods.

— annette m. kim, The Atlantic, "Satellite Images Can Harm the Poorest Citizens," 5 June 2018
Some of the same parameters are taking shape in California, equally known for black-market pot from its Emerald Triangle region.

— gillian flaccus, The Christian Science Monitor, "Oregon faces fallout from a flooded marijuana market," 31 May 2018
The truth is that the parameters surrounding proper electrolyte consumption remain vague and largely undeveloped.

— sara angle, Outside Online, "Your Guide to Using Electrolytes Properly," 21 May 2018
Oak Lawn Division Chief Ross Finnelly said Thursday that several village officers were negotiating the parameters of a private weekend security detail at the Miami, but that the deal had not been finalized.

— zak koeske, Daily Southtown, "Oak Lawn hits budget motel with $20K fine, orders security upgrade," 27 Apr. 2018
Commissioners Daina Chiu, Quentin Kopp and Yvonne Lee noted that Alioto could have included donations received on March 27 as part of her funding application, but that the committee had not been aware of those parameters.

— rachel swan, San Francisco Chronicle, "SF mayor candidate Alioto to get another crack at matching campaign funds," 23 Apr. 2018
Who thinks the University of Kentucky basketball is going to die any time soon, regardless of college basketball's parameters?

— mac engel, star-telegram, "'Don't put restrictions on kids': Calipari's one-and-done stance is dead on | Fort Worth Star-Telegram," 20 Apr. 2018
The university allows and empowers all students to freely express themselves within these important parameters.

— gregory germain, Washington Post, "Law professor: Syracuse betrayed its commitment to free speech when it punished fraternity members for their videos," 11 June 2018

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.

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