oat

oat /ˈoʊt/ noun
plural oats
oat
/ˈoʊt/
noun
plural oats
Britannica Dictionary definition of OAT
1 
[noncount] : a kind of grain that is widely grown — often used before another noun
2 
oats [plural] : the seeds of the oat plant used as feed for farm animals and in foods (such as bread and oatmeal) for people

feel your oats

US, informal
: to feel new confidence and energy

sow your (wild) oats

— see 1sow