[oat] n, often attrib [ME ote, fr. OE ate] (bef. 12c) 1 a: any of several grasses (genus Avena); esp: a widely cultivated cereal grass (A. sativa) b: a crop or plot of the oat; also: oat seed--usu. used in pl. but sing. or pl. in constr.
2. archaic: a reed instrument made of an oat straw