geoids

Noun

geoid (plural geoids)

1. The shape, extending through landmasses (continents, etc.), that the surface of the oceans of the Earth would take under the influence of the Earth's gravity and rotation alone, disregarding other factors such as winds and tides; that is, a surface of constant gravitational potential at zero elevation.
   • The problem of the form and dimensions of the sea level surface of the earth has been one of peculiar difficulty. The combined efforts of the ablest mathematicians of the past two centuries, supplemented by the most laborious and costly geodetic measurements have yielded us the first approximation...1888, Robert Simpson Woodward, “Introduction”, in On the Form and Position of the Sea Level: With Special Reference to Its Dependence on Superficial Masses Symmetrically Disposed about a Normal to...