diet (n.1)
c. 1200, “regular food,” from Old French diete (13c.) “diet, pittance, fare,” from Medieval Latin dieta “parliamentary assembly,” also “a day’s work; daily food allowance, food,” from Latin diaeta “prescribed way of life,” from Greek diaita, originally “way of life, regimen, dwelling,” related to diaitasthai “lead one’s life,” and from diaitan, originally “separate, select” (food and drink), frequentative of *diainysthai “take apart,” from dia “apart” (see dia-) + ainysthai “take,” from PIE root *ai- (1) “to give, allot.”
From late 14c. as “customary way of eating,” also “food considered in relation to its quantity and effects,” and “a course of food regulated by a physician or by medical rules,” often a restriction of food or certain foods; hence to put (someone) on a diet (mid-15c.). The adjective in the sense of “slimming, having reduced calories” (Diet Coke, etc.) is attested by 1963, originally in American English.
Related entries & more
“assembly of delegates, etc., held from day to day for legislative, political, or other business,” mid-15c., from Medieval Latin dieta, variant of diaeta “daily office (of the Church), daily duty, assembly, meeting of counselors,” from Greek diaita “regimen” (see diet (n.1)), but associated with Latin dies “day” (from PIE root *dyeu- “to shine”). Since c. 1600 used by English and French writers of the legislative assemblies of Germany and Austria.
late 14c., “to regulate one’s diet for the sake of health,” from Old French dieter, from diete “fare” (see diet (n.1)); meaning “to regulate oneself as to food” (especially against fatness) is from 1650s. Related: Dieted; dieting. An obsolete word for this is banting.
c. 1400, “act of eating; act of regulating food intake according to regimen,” verbal noun from diet (v.).
also aetiology, aitiology, “science of causes or causation,” 1550s, from Late Latin aetiologia, from Greek aitiologia “statement of cause,” from aitia “cause, responsibility” (from PIE *ai-t-ya-, from root *ai- (1) “to give, allot;” see diet (n.1)) + -logia “a speaking” (see -logy). Related: Etiologic; etiological.
“pertaining to diet,” 1610s, from Medieval Latin dietarius, from Latin diaetarius, from diaeta “prescribed way of life” (see diet (n.1)).
“pertaining to a diet in the ‘assembly’ sense,” 1845; see diet (n.2) + -al (1).
“one who practices some theory of diet,” 1845, from diet (n.1) on model of physician. Earlier was dietist (c. 1600).
“pertaining to the rules for regulating the kind and quantity of food taken,” 1570s, from Latin diaeteticus, from Greek diaitetikos “of or pertaining to diet,” from diaita “way of life, regiment” (see diet (n.1)). Related: Dietical (1610s).
Proto-Indo-European root meaning “to shine,” in derivatives “sky, heaven, god.”
It forms all or part of: adieu; adios; adjourn; Asmodeus; circadian; deific; deify; deism; deity; deodand; deus ex machina; deva; dial; diary; Diana; Dianthus; diet (n.2) “assembly;” Dioscuri; Dis; dismal; diurnal; diva; Dives; divine; joss; journal; journalist; journey; Jove; jovial; Julia; Julius; July; Jupiter; meridian; Midi; per diem; psychedelic; quotidian; sojourn; Tuesday; Zeus.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit deva “god” (literally “shining one”); diva “by day;” Avestan dava- “spirit, demon;” Greek delos “clear;” Latin dies “day,” deus “god;” Welsh diw, Breton deiz “day;” Armenian tiw “day;” Lithuanian dievas “god,” diena “day;” Old Church Slavonic dini, Polish dzień, Russian den “day;” Old Norse tivar “gods;” Old English Tig, genitive Tiwes, name of a god.
Source: O
etymonline.com
oxford dictionary