| 释义 |
geoid|ˈdʒiːɔɪd|
[ad. Gr. γεοειδής, adj., earthlike, f. γεο-, γῆ earth + εἶδος form: see -oid.
First used in German (geoide) by Listing, Ueber unsere jetzige Kenntniss der Gestalt u. Grösze der Erde (1872).]
A geometrical solid, nearly identical with the terrestrial spheroid, but having the surface at every point perpendicular to the direction of gravity.
1881M. Merriman Fig. Earth 79 The word Geoid is used to designate the actual figure of the surface of the waters of the earth..The geoid, then, is an irregular figure peculiar to our planet. 1883Nature 15 Mar. 471 The geoid (or the true figure of the earth's surface, as determined by the directions of the pendulum) nearly corresponds with the spheroid on the shores of the Black Sea.
¶ Misused for geode.
1839Bailey Festus xx. (1848) 261 And even when their looks are earthy, still If opened, like geoids, they may be found Full of all sparkling sparry loveliness.
Hence geˈoidal a., of or pertaining to a geoid.
1881M. Merriman Fig. Earth 79 The second definition determines that our geoidal surface to be investigated is that coinciding with the surface of the great oceans. |