geoidPronunciation: /ˈdʒiːɔɪd/Definition of geoid noun (the geoid) a hypothetical solid figure whose surface corresponds to mean sea level and its imagined extension under (or over) land areas. Origin: late 19th century: from Greek geoeidēs, from gē 'earth' + -oeidēs (see -oid)geoid in other Oxford dictionaries Definition of geoid in the US English dictionary
