The term "plant eater" describes an animal that primarily feeds on vegetation. Synonyms for this term include herbivore, a term commonly used in reference to many mammals such as deer, cows, and sheep. Vegetarian is a term used to refer to humans who consume a plant-based diet, but can also be used to refer to animals that consume only plant-based foods. Folivore describes animals that consume mainly leaves, while frugivore refers to animals that consume mainly fruits. Lastly, grazer refers to animals that feed mainly on grasses and other low-lying plants, and browser refers to animals that feed on the leaves and twigs of trees and bushes.