follow Dictionary.com

Love words? Sign up for our Word of the Day!

geoid

[jee-oid] /ˈdʒi ɔɪd/
noun
1.
an imaginary surface that coincides with mean sea level in the ocean and its extension through the continents.
2.
the geometric figure formed by this surface, an ellipsoid flattened at the poles.
Origin
1880-1885
1880-85; < Greek geoeidḗs earthlike. See geo-, -oid
Related forms
geoidal, adjective
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
British Dictionary definitions for geoidal

geoid

/ˈdʒiːɔɪd/
noun
1.
a hypothetical surface that corresponds to mean sea level and extends at the same level under the continents
2.
the shape of the earth
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
geoidal in Science
geoid
  (jē'oid')   
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 © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Encyclopedia Article for geoidal

geoid

model of the figure of the Earth-i.e., of the planet's size and shape-that coincides with mean sea level over the oceans and continues in continental areas as an imaginary sea-level surface defined by spirit level. It serves as a reference surface from which topographic heights and ocean depths are measured. The scientific discipline concerned with the precise figure of the Earth and its determination and significance is known as geodesy.

Learn more about geoid with a free trial on Britannica.com
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source

Word of the Day

Difficulty index for geoid

Some English speakers likely know this word

Word Value for geoidal

9
11
Scrabble Words With Friends