1. a. The land surface of the world. b. The softer, friable part of land; soil, especially productive soil. 2. often Earth The third planet from the sun, having a sidereal period of revolution about the sun of 365.26 days at a mean distance of approximately 149 million kilometers (92.96 million miles), an axial rotation period of 23 hours 56.07 minutes, an average radius of 6,378 kilometers (3,963 miles), and a mass of approximately 5.974 × 1024 kilograms (1.317 × 1025 pounds). 3. The realm of mortal existence; the temporal world. 4. The human inhabitants of the world: The earth received the news with joy.