(Biology)a substance required in relatively large amounts by living organisms, in particular (生)大量养料;常量营养物,尤指 ■a type of food (e.g. fat, protein, carbohydrate) required in large amounts in the diet 主要养分(如脂肪、蛋白质、碳水化合物) ■a chemical element (e.g. potassium, magnesium, calcium) required in large amounts for plant growth and development 常量营养素(如钠、钾、钙)