1. In biological energetics, food; or any substance which provides the specific elements necessary for the growth, maintenance, and reproduction of living organisms: There are countless kinds of nutrients, some of which are yolks of eggs, water, milk, flour, tapioca, cocoa, etc.
2. A substance that provides nourishment: The nutrients consist of minerals that a plant takes from the soil or the constituents in food that keep a human body healthy and help it to grow.