the word is a transparent modern english compound, formed by combining two old english nouns. "wheat" derives from the proto-germanic "hwaitijaz", related to "white", likely referring to the light color of the refined flour. "grass" comes from proto-germanic "grasan", meaning a green herbage or pasture. the compound "wheatgrass" is a descriptive term from the 20th century, specifically denoting the young, green shoots of the wheat plant (triticum aestivum) when used for juicing or as a supplement. it logically names the plant by its species origin ("wheat") and its form at the stage of consumption ("grass").

Structure: wheat (cereal plant) + grass (herbaceous plant) "wheat" from old english "hwæte" (meaning "wheat"), of germanic origin. "grass" from old english "græs" (meaning "herb, plant, grass"), of germanic origin.