oat

noun

ˈōt 

often attributive

1

a

: any of several grasses (genus Avena)

especially : a widely cultivated cereal grass (A. sativa)

b

: a crop or plot of the oat

also : the seed of an oat

—usually used in plural but singular or plural in construction

2

archaic : a reed instrument made of an oat straw

Illustration of oat

• oat 1a

Phrases

feel one's oats

: to act in a newly self-confident and often self-important manner

Examples of oat in a Sentence

Recent Examples on the Web

Mix in oat flakes and baking powder. —Laura Solla, Vogue, 30 Oct. 2025

It’s packed with calming ingredients like oat kernel extract, beta-glucan, and panthenol to support the skin barrier, while glycerin helps lock in moisture. —Christa Joanna Lee, Allure, 30 Oct. 2025

For a balanced breakfast, combine the two—mix yogurt into your oats or alternate between them for variety. —Julia Ries Wexler, Health, 30 Oct. 2025

Breakfast Cereal Whole-grain cereals, such as those made from oats or whole wheat, are rich in fiber, which supports digestion, promotes heart health, and helps regulate blood sugar. —Lauren Panoff, Verywell Health, 29 Oct. 2025

Word History

Etymology

Middle English ote "the grain of the oat plant, the plant itself," going back to Old English āte (weak feminine noun), of uncertain origin

Note: Old English āte has been compared with regional Dutch aate, oote "wild oats" (West and Zeeland Flanders), West Frisian and Groningen Dutch oat. (These contrast with Dutch haver, denoting cultivated oats, a reflex of the Common Germanic word for the grain.) Michiel de Vaan, in an addenda to the online etymologiebank.nl, believes that the Flanders words are semantic extensions of regional aat "food," of general Germanic origin (see eat entry 2), though this hypothesis would scarcely explain the Old English word. Jan de Vries (Nederlands Etymologisch Woordenboek, Brill, 1971) hypothesizes that the Low Country words may have been borrowed from English.

First Known Use

before the 12th century, in the meaning defined at sense 1a

Phrases Containing oat

• oat cell
• oat grass
• oat milk
• wild oat

Rhymes for oat

• bloat
• boat
• choate
• coat
• cote
• dote
• float
• gloat
• goat
• groat
• haute
• moat

Kids Definition

oat

noun

ˈōt 

: a grain that is widely grown for its long loose clusters of seeds which are used for human food and for livestock feed

oaten

ˈōt-ᵊn

adjective