soy(n = noun.food) soya, soya bean, soybean - 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);
A Chinese and Japanese liquid sauce for fish, etc., made by subjecting boiled beans (esp. soybeans), or beans and meal, to long fermentation and then long digestion in salt and water. [1913 Webster]