The term "terrestrial" refers to anything related to the Earth or land. It is often used to describe living organisms that inhabit land environments, such as terrestrial animals like elephants and lions. These creatures have adapted to life on solid ground, as opposed to those that live in water, known as aquatic animals. In addition to animals, "terrestrial" can also describe plants that grow on land, such as trees and flowers. These plants play a crucial role in our ecosystem by providing oxygen and food. Overall, the concept of "terrestrial" encompasses a wide range of life forms and environments found on our planet.