Webster's Revised Unabridged Dictionary · 1913

Buckwheat

Buckwheat ({not transcribed}) , noun

[Buck a beech tree + wheat; akin to Dutch boekweit, German buchweizen.]

1.
(Botany) A plant (Fagopyrum esculentum) of the Polygonum family, the seed of which is used for food.
2.
The triangular seed used, when ground, for griddle cakes, etc.