Etymologically
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dietary

This is the current revision of this entry, as edited by bogdan on 24 October 2026 at 18:39. This address is a permanent link to this version.
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Pronunciation

  • UK: /ˈdaɪət(ə)ɹi/[1]
  • US: /ˈdaɪəˌtɛɹi/[1]

Etymology

It is inherited from Middle English dietarie, also diatorie,[2][3][4] borrowed from Medieval Latin diētārium (“a book prescribing a diet or rule of living”),[5][2][6][7] recorded from the 13th century in British sources,[5] from Latin diaeta (“diet, prescribed way of life”) and the suffix -ārium.[5][7] The Latin noun comes from Ancient Greek δίαιτα (díaita, “way of life, regimen, dwelling”),[8] the source of diet.[8][7] The OED compares diaetārius (“house-steward”).[5] Etymonline derives the adjective from Medieval Latin dietarius,[8] while Merriam-Webster takes it as formed in English from diet and -ary.[3]

Earliest recorded meaning

A prescribed course of diet, and a treatise prescribing one: about 1450, in Lydgate's “Diatorie”, "To be rulid bi þis diatorie do þi diligence".[2][5]

Semantic evolution

In Middle English alchemy the noun also named a prescribed method of regulating the growth of the dry matter.[2] The adjective, "relating to a prescribed diet", is recorded from 1585 in the OED,[5] and since 1614 in Merriam-Webster;[3] Etymonline dates it to the 1610s.[8] Johnson (1755) defined it as "pertaining to the rules of diet".[9] From 1789, in John Howard, the noun was used of the scheme by which the inmates of an infirmary, workhouse or prison were fed, and of the food served to them.[5][7] The adjective later came to refer generally to what a person or animal eats,[5][3] and the noun to the food eaten by a person or population: Lewis Mumford wrote that "New food crops..enriched the dietary of Europe".[7][3] The old sense "a rule of diet" is now obsolete.[3]

Timeline

  • c. 1450 – a prescribed diet; a treatise on diet.[5][2]
  • 1585 – adjective, relating to a prescribed diet.[5]
  • 1614 – adjective, relating to diet.[3]
  • 1755 – Johnson: pertaining to the rules of diet.[9]
  • 1789 – the scheme for feeding the inmates of an institution.[5]

Modern meaning

Adjective

  1. Relating to diet, the food that a person or animal usually eats: Her dietary needs changed after the operation.
  2. Relating to the rules of a prescribed diet: The clinic gives dietary advice to patients with diabetes.

Noun

  1. A regulated allowance of food, as in a hospital or prison.
  2. The food eaten by a person, group or population.
  3. (obsolete) A rule of diet, or a book on such rules.

Word family

  • dietarily
  • predietary
  • dietary fiber
  • dietary supplement
  • diet
  • dietetic
  • dietitian

References

  1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
  3. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  4. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  5. ^ a b c d e f g h i j k Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  6. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
  7. ^ a b c d e Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  8. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  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.