# parameter

## noun

pa·​ram·​e·​ter
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
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
usually used in plural
the parameters of science fiction
The investigation stayed within the parameters set by the court.

## Did you know?

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 The number of parameters is a key metric of an AI model’s size and usually, but not always, correlates to performance. John Kang, Forbes, 19 Feb. 2024 The profile is the second parameter that the Royals use with their new slogan. Jaylon Thompson, Kansas City Star, 18 Feb. 2024 So, there's no insight into key parameters regarding the craft's propulsion, power, or control systems. Jon Brodkin, Ars Technica, 6 Feb. 2024 Republicans, who have criticized the justice system reform bills passed by the legislature in recent years and focused on crime — particularly in Baltimore City and Prince George’s County — are encouraged by the bill’s parameters. Hannah Gaskill, Baltimore Sun, 1 Feb. 2024 The challenge, Posen notes, was refashioning the ball within historical parameters that also aligned aesthetically with the Ryan Murphy Cinematic Universe. Hannah Jackson, Vogue, 7 Feb. 2024 One of the ideas involves switching the computer to operate in different modes, such as the operating parameters the FDS used when Voyager 1 was flying by Jupiter and Saturn in 1979 and 1980. Jon Brodkin, Ars Technica, 6 Feb. 2024 These connections are known as the model’s parameters, and their number denotes the LLM’s size. Quanta Magazine, 22 Jan. 2024 If police willfully do not follow the parameters of the law, any statement made by the minor in question would be inadmissible in court. Hannah Gaskill, Baltimore Sun, 17 Jan. 2024 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'parameter.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

## Word History

Etymology

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

First Known Use

1833, in the meaning defined at sense 1a

Time Traveler
The first known use of parameter was in 1833

parameter

## Cite this Entry

“Parameter.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/parameter. Accessed 26 Feb. 2024.

## Kids Definition

parameter

noun
pa·​ram·​e·​ter
1
: an independent variable used to express the coordinates of a point
if the coordinates (x, y) of a point are given by the functions x = f(t) and y = g(t) then the parameter is the variable t
2
: any of a set of properties whose values determine the characteristics or behavior of something
parameters of the atmosphere such as temperature, pressure, and density