buck ‧ wheat /ˈbʌkwiːt/ BrE AmE noun [uncountable]
[ Date: 1500-1600 ; Language: Middle Dutch ; Origin: boecweit , from boec 'beech' + weit 'wheat' ; because the grains are the same shape as beech-tree seeds ]
a type of small grain used as food for chickens, and for making flour