parameter

Etymology

It is borrowed from New Latin parameter, also parametrum,^{[2][3][4][5][6]} found in C. Mydorge's Latin treatise on conic sections of 1631, which defines the parametrum of a conic section.^[2] It is formed from Ancient Greek παρα- (para-, “beside, subsidiary”) and μέτρον (métron, “measure”),^[3][7][4][8] the latter through the Latin combining form -metrum (English -meter);^[2][5] Etymonline traces the Greek noun to Proto-Indo-European *me- (“to measure”).^[3] The OED compares French paramètre, used in mathematics from 1636.^[2]

Earliest recorded meaning

In geometry, (the length of) a chord through the focus of a conic section bisected by a given diameter: 1656, in Thomas Hobbes's Six Lessons.^[2][7] Johnson (1755) explained it as the latus rectum of a parabola.^[9]

Semantic evolution

The word stayed a technical term of geometry until the late 1920s.^[3] In astronomy (1829) it named each of the numbers that specify a planet's or comet's orbit;^[2] in mathematics, a quantity fixed in a particular case but variable in others, from 1833 in the OED and Merriam-Webster^[2][10] (1852 in Barnhart),^[7] and since 1855 an independent variable in terms of which the coordinates of a curve are expressed;^[2] in crystallography (1839) the intercept of a face on an axis;^[2] in electrical engineering (1911) a quantity characterizing a circuit;^[2] and in statistics (1920) a numerical characteristic of a population, as distinct from a sample.^[2] From the late 1920s it was extended to any measurable factor that helps to define a system;^[2][3][7] from this, partly under the influence of perimeter, came the general sense "a boundary, limit, defining characteristic", common from the 1950s.^[7][3] Music took it up in 1968 for a quantifiable feature such as pitch or rhythm, and in 1983 for a user-controlled setting of a synthesizer.^[2]

Timeline

• 1631 – Latin parametrum, in Mydorge.^[2]
• 1656 – in geometry, a chord through the focus of a conic.^[2][7]
• 1829 – in astronomy, an element of an orbit.^[2]
• 1833 – in mathematics, a constant that varies from case to case.^[2][10]
• 1839 – in crystallography.^[2]
• 1920 – in statistics, a characteristic of a population.^[2]
• 1927 – a defining or measurable characteristic of something.^[2][7]
• 1950s – the general sense of a boundary or limit.^[7][3]
• 1968 – in music, a quantifiable feature such as pitch.^[2]

Meanings

Noun

1. (mathematics) A quantity that is constant in a given case but may vary in others, such as a constant whose value distinguishes the members of a family of curves.^[10][2][11]
2. (mathematics) An independent variable in terms of which the coordinates of a point are expressed, as in parametric equations.^[2][12][11]
3. (statistics) A numerical characteristic of a population, such as its mean, as distinct from one obtained from a sample.^[2][12][11]
4. Any of a set of measurable properties that determine how a system behaves: the parameters of the climate model.^[11][2]
5. (usually plural) A limit or boundary; a defining characteristic or factor: We must work within the parameters of the budget.^[2][7][11]
6. (geometry) A chord through the focus of a conic section bisected by a given diameter; the latus rectum.^[2][5][9]
7. (crystallography) The intercept made by a crystal face on one of the axes.^[10][2]

Word family

• parametric
• parametrically
• parameterize

Related words

• parametrize
• perimeter
• meter
• metric
• diameter

Usage notes

The OED notes adverse comment from later 20th-century usage guides, which see them as loose transfers of the mathematical and computing use and confuse the word with perimeter, as in Sir Bruce Fraser's revision of Gowers's Complete Plain Words (1973).^[2] The American Heritage Dictionary calls parameter the archetype of a scientific term borrowed into general use, which has drawn much skeptical comment.^[13] Dictionary.com notes that some readers object strongly to these senses, but that they are well established in educated speech and edited writing,^[14] while Grammarphobia complains that the word is now used for almost anything but its scientific meaning.^[15]

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z 27 28 29 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
5. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
7. ^ a b c d e f g h i Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
8. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
10. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
11. ^ a b c d e Merriam-Webster's Collegiate Dictionary (2003), 11th ed., Springfield, Mass.: Merriam-Webster
12. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins
13. ^ The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin
14. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
15. ^ O'Conner, Patricia T.; Kellerman, Stewart, The Grammarphobia Blog, grammarphobia.com, p. "Parameter insecurity", 8 June 2007