Etymologically
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perimeter

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Pronunciation

  • UK: /pɪˈɹɪm.ɪ.tə/[1]
  • US: /pəˈɹɪm.ɪ.təɹ/[1]

Etymology

It is inherited from Middle English perimetre,[2][3][4] borrowed from Latin perimetros (“circumference”),[5][2][3][4] from Ancient Greek περίμετρος (perímetros), a noun use of the Greek adjective meaning "going round, circumferential".[5][3] The Greek word is formed from περι- (peri-, “around”) and μέτρον (métron, “measure”),[5][2][6][7] and Etymonline traces the second part to Proto-Indo-European *me- (“to measure”).[2] The OED compares the Greek neuter περίμετρον (perímetron),[5] which Dictionary.com gives as the direct Greek source.[8] Collins, Hoad, Klein and Dictionary.com instead take the modern word through French périmètre and date it to the 16th century,[9][10][7][8] while the OED, Barnhart and the Oxford Dictionary of English find it in late Middle English.[5][3][11]

Earliest recorded meaning

A continuous line forming the boundary of a figure or a surface; a circumference: before 1425, in an English translation of Guy de Chauliac's Grande Chirurgie.[5] Barnhart dates the first record to probably before 1425,[3] and Etymonline to the early 15th century.[2]

Semantic evolution

The word began as a term of geometry, for the line round a figure and for the length of that line.[5][6] Johnson (1755) defined it as the sum of all the sides that bound any figure, whether straight or curved.[12] From the early 17th century it was used more loosely and figuratively for a ring or space around something, an edge or a limit, as in Ben Jonson's Magnetick Lady (before 1637); in this use it is sometimes confused with parameter.[5] The military sense, the defended boundary of a position, is recorded from 1861 in the OED,[5] and by 1943 in Etymonline;[2] it spread to the boundary of a prison, an airfield or an airport.[5] In ophthalmology a perimeter has been an instrument for measuring the field of vision since 1875,[5][9] and in basketball the word has meant the area beyond the three-point line since 1959,[5] when it also came into use as an adjective for players and shots from that area.[13]

Timeline

  • before 1425 – the boundary line of a figure or surface; a circumference.[5][3]
  • 1585–95 – the date Dictionary.com gives for the word, borrowed through French.[8]
  • before 1637 – figurative: a ring around something, an edge or limit.[5]
  • 1755 – Johnson defines it as the sum of the sides bounding a figure.[12]
  • 1861 – military: the defended boundary of a position.[5]
  • 1875 – ophthalmology: an instrument for measuring the field of vision.[5]
  • 1959 – basketball: the area beyond the three-point line; also as an adjective.[5][13]

Meanings

Noun

  1. The boundary of a closed plane figure: the perimeter of a triangle.[13][9][5]
  2. The length of such a boundary, as the sum of the sides of a polygon.[13][9][5]
  3. The outer edge or boundary of any area: Guards walked the perimeter of the airfield every hour.[9][13][5]
  4. The fortified boundary of a military position.[5][6]
  5. In basketball, the area of the court away from the basket, beyond the three-point line.[13][5]
  6. An instrument for measuring the extent of the field of vision.[9][5]

Adjective

  1. In basketball, playing or scoring mostly from the perimeter: a perimeter shooter.[13]

Word family

  • perimetric
  • perimetrically
  • perimeterless
  • perimetral
  • perimetry
  • isoperimeter

References

  1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  3. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  4. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  5. ^ a b c d e f g h i j k l m n o p q r s t u v w Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  6. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  7. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
  8. ^ a b c Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  9. ^ a b c d e f Collins English Dictionary (2023), Glasgow: HarperCollins
  10. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
  11. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
  12. ^ 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.
  13. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster