From Middle English ote, from Old English āte, from Proto-Germanic *aitǭ (“swelling; gland; nodule”), from Proto-Indo-European *h₁eyd- (“to swell”). See English atter.
oat (countable and uncountable, plural oats)
- (uncountable) Widely cultivated cereal grass, typically Avena sativa.
- (countable) Any of the numerous species, varieties, or cultivars of any of several similar grain plants in genus Avena.
- (usually as plural) The seeds of the oat, a grain, harvested as a food crop.
- A simple musical pipe made of oat-straw.