- an imaginary surface that coincides with mean sea level in the ocean and its extension through the continents.
- the geometric figure formed by this surface, an ellipsoid flattened at the poles.
Origin of geoid
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for geoid
The reduction of triangulation base lines from the geoid to the reference ellipsoid.
The geoid is defined as the average level of the sea, which is thought of as extended through the continents.
In physical geodesy, gravimetric data are used for the determination of the geoid and components of deflections of the vertical.
The west-European and the Russo-Scandinavian meridians indicate another anomaly of the geoid.
It's geoid teah is this; aw've monny a time ta'en a gooid swig aght o' that teah-pot before to-day.Yorksher Puddin'
- a hypothetical surface that corresponds to mean sea level and extends at the same level under the continents
- the shape of the earth
- The hypothetical surface of the Earth that coincides everywhere with mean sea level and is perpendicular, at every point, to the direction of gravity. The geoid is used as a reference surface for astronomical measurements and for the accurate measurement of elevations on the Earth's surface.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.