n.1. Material, especially carbohydrates, fats, and proteins, that an organism uses for energy, growth, and maintaining the processes of life. Plants, algae, and some bacteria make their own food through photosynthesis, while animals and most other organisms obtain food by consuming other organisms or organic matter.
2. A specified kind of nourishment: breakfast food; plant food.
3. Nourishment eaten in solid form: food and drink.
4. Something that nourishes or sustains in a way suggestive of physical nourishment: food for thought.