An Etymological Dictionary of Astronomy and Astrophysics

The form of the → Earth obtained by taking average sea level surface and extending it across the continents. In other words, the → equipotential surface (“mean sea level”) of the Earth’s → gravitational field. The geoid is considered to represent the true physical figure of the Earth, in contrast to the → reference ellipsoid, which is idealized geometrical figure of the Earth.

See also: → geo-; → -oid.