TERRA is a Latin word meaning 'EARTH' or 'LAND'. The term is used in various contexts, including geography, geology, and astronomy. COTTA is an Italian word meaning 'CLAY', EARTH is an English word meaning 'the planet on which we live', FIRMA is a Latin word meaning 'FIRM' or 'SOLID', and PLANETEARTH is an English phrase meaning 'the planet on which we live'. Together, these five terms all refer to the same thing: the planet EARTH.