Herbivorous describes an animal that eats only plants. A cow is herbivorous because it grazes on grass and hay. Deer are herbivorous, browsing on leaves, twigs, and bark. Giant pandas are herbivorous too, spending most of their day munching bamboo.

Herbivorous animals have bodies specially adapted for their plant-based diet. Many have flat teeth perfect for grinding tough plant material, unlike the sharp teeth of meat-eaters. Some, like cows and sheep, even have multiple stomach chambers to help break down all that plant matter.

Scientists use herbivore as the noun form to describe these plant-eaters, and you'll often see animals grouped as herbivores, carnivores (meat-eaters), or omnivores (animals that eat both plants and meat). The largest land animals, from elephants to giraffes to the enormous sauropod dinosaurs that once roamed Earth, were herbivorous. It turns out you can grow pretty big eating nothing but plants.