soybean (Noun) — A source of oil; used for forage and soil improvement and as food.
soybean (Noun) — Erect bushy hairy annual herb having trifoliate leaves and purple to pink flowers; extensively cultivated for food and forage and soil improvement but especially for its nutritious oil-rich seeds; native to Asia.
soybean (Noun) — The most highly proteinaceous vegetable known; the fruit of the soybean plant is used in a variety of foods and as fodder (especially as a replacement for animal protein).