oat, n.
1 a a cereal plant, Avena sativa, cultivated in cool climates. b (in pl.) the grain yielded by this, used as food.
2 any other cereal of the genus Avena, esp. the wild oat, A. fatua.
3 poet. the oat-stem used as a musical pipe by shepherds etc., usu. in pastoral or bucolic poetry.
4 (in pl.) sl. sexual gratification.
feel one's oats colloq.
1 be lively.
2 US feel self-important. oat-grass any of various grasses, esp. of the genus Arrhenatherum. off one's oats colloq. not hungry. sow one's oats (or wild oats) indulge in youthful excess or promiscuity.
oaten adj.
OE ate, pl. atan, of unkn. orig.