diet

1 of 4

noun (1)

di·​et ˈdī-ət 

1

a

: food and drink regularly provided or consumed

a diet of fruits and vegetables

a vegetarian diet

b

: habitual nourishment

links between diet and disease

c

: the kind and amount of food prescribed for a person or animal for a special reason

was put on a low-sodium diet

d

: a regimen of eating and drinking sparingly so as to reduce one's weight

going on a diet

2

: something provided or experienced repeatedly

Their imaginations feverish from a diet of detective novels …

—The New Yorker

heard a steady diet of excuses

diet

2 of 4

verb

dieted; dieting; diets

transitive verb

1

: to cause to take food : feed

2

: to cause to eat and drink sparingly or according to prescribed rules

intransitive verb

: to eat sparingly or according to prescribed rules

has been dieting for two months

dieter noun

diet

3 of 4

adjective

1

: reduced in or free from calories

a diet soft drink

2

: promoting weight loss (as by depressing appetite)

diet pills

diet

4 of 4

noun (2)

1

: a formal deliberative assembly of princes or estates

2

: any of various national or provincial legislatures

Did you know?

The word diet first appeared in English in the 13th century. Its original meaning was the same as in modern English, “habitually taken food and drink.” But diet was used in another sense too in the Middle and early modern English periods to mean “way of living.” This is, in fact, the original meaning of diet’s Greek ancestor diaita, which is derived from the verb diaitasthan, meaning “to lead one’s life.” In Greek, diaita, had already come to be used more specifically for a way of living prescribed by a physician, a diet, or other regimen.

Examples of diet in a Sentence

Verb

I've been dieting for two months.

Recent Examples on the Web

Noun

During three trials, participants were assigned to specific healthy diets — such as low-fat, low-carb, Mediterranean and green-Mediterranean — for 18 to 24 months. —Angelica Stabile, FOXNews.com, 19 June 2025

Geese and cranes differ in many ways, such as diet, behavior and migration strategies. —Anne Readel, Smithsonian Magazine, 18 June 2025

Verb

When dieting or losing weight, ghrelin levels tend to rise while leptin levels typically decrease.13 Essentially, ghrelin and leptin work together to control your appetite by sending hunger and satiety cues. —Brittany Lubeck, Ms, Rdn, Verywell Health, 14 Apr. 2025

These options use similar artificial sweeteners to diet sodas and don't contain significant nutritional value. —Cristina Mutchler, Verywell Health, 3 Feb. 2025

Adjective

Even as obesity is rising, Big Food and dietitians are pushing ‘anti-diet’ advice. —Rachel Zimmerman, Washington Post, 30 June 2024

To avoid San Francisco’s tax on sugary drinks, Costco chose to serve only diet sodas or unsweetened tea in its food courts. —Byirina Ivanova, Fortune, 1 June 2024

Word History

Etymology

Noun (1), Verb, and Adjective

Middle English diete, from Anglo-French, from Latin diaeta, from Greek diaita, literally, manner of living, from diaitasthai to lead one's life

Noun (2)

Middle English diete day's journey, day set for a meeting, from Medieval Latin dieta, literally, daily regimen, diet (taken as a derivative of Latin dies day), from Latin diaeta — see diet entry 1

First Known Use

Noun (1)

13th century, in the meaning defined at sense 1a

Verb

14th century, in the meaning defined at transitive sense 1

Adjective

1963, in the meaning defined at sense 1

Noun (2)

1565, in the meaning defined at sense 1

Phrases Containing diet

• caveman diet
• crash diet
• keto diet
• ketogenic diet
• Mediterranean diet
• on a diet
• paleo diet
• paleolithic diet
• staple diet
• starvation diet
• Stone Age diet

Rhymes for diet

• guyot
• piet
• quiet
• riot
• disquiet
• panchayat
• unquiet

Kids Definition

diet

1 of 4 noun

di·​et ˈdī-ət 

1

a

: the food and drink that a person, animal, or group usually takes

many birds live on a diet of insects

b

: the kind and amount of food selected for a person or animal for a special reason (as improving health)

a high-protein diet

c

: a plan of eating and drinking less than usual so as to reduce one's weight

going on a diet

2

: something experienced repeatedly

a steady diet of television

diet

2 of 4 verb

: to eat or cause to eat less or according to special rules

diet

3 of 4 adjective

: reduced in calories

a diet soft drink

diet

4 of 4 noun

: a body of lawmakers : legislature

Etymology

Noun

Middle English diete "regular food, diet," from early French diete (same meaning), derived from Greek diaita, literally, "manner of living"

Noun

Middle English diete "day's journey, day set for a meeting," from Latin dieta, literally, "daily regimen, diet" (associated with Latin dies "day"), derived from Greek diaita

Medical Definition

diet

1 of 3 noun

di·​et ˈdī-ət 

1

: food and drink regularly provided or consumed

2

: habitual nourishment

3

: the kind and amount of food prescribed for a person or animal for a special reason

4

: a regimen of eating and drinking sparingly so as to reduce one's weight

going on a diet

diet

2 of 3 transitive verb

1

: to cause to take food

2

: to cause to eat and drink sparingly or according to prescribed rules

intransitive verb

: to eat sparingly or according to prescribed rules

diet

3 of 3 adjective

1

: reduced in calories or without calories

a diet soft drink

2

: promoting weight loss (as by depressing appetite)

diet pills