1. of, relating to, or having the shape of a geoid; approximating the shape of the Earth as defined by mean sea level and gravitational equipotential surfaces.
Usage: technical; used in geodesy, geophysics, and cartography

Examples

• The geoidal surface represents the true gravitational equipotential of the Earth.
• Surveyors must account for geoidal undulations when measuring precise elevations.
• GPS measurements are often referenced to a geoidal model rather than a perfect sphere.
• The geoidal shape of the planet differs slightly from an oblate spheroid.
• Geoidal heights are essential for accurate coastal and hydrographic mapping.