hemisphere

The story

1. Ancient Greek · derived fromἡμισφαίριον
2. Latin · derived fromhemisphaerium
3. English todayhemisphere

From Latin hemisphaerium, from Ancient Greek ἡμισφαίριον (hēmisphaírion), from ἡμι- (hēmi-, “half”) + σφαῖρα (sphaîra, “sphere”). Equivalent to hemi- + sphere. Displaced native Old English healftrendel (literally “half-sphere”).

First known use, by meaning

• from 14th c. Half of the celestial sphere, as divided by either the ecliptic or the celestial equator .
• 1503 A realm or domain of activity .
• 1550s Half of the Earth, such as the Northern Hemisphere, Southern Hemisphere, Western Hemisphere or Eastern Hemisphere, Land Hemisphere, Water Hemisphere etc. .
• 1580s Any half-sphere, formed by a plane intersecting the center of a sphere. .
• 1706 A map or projection of a celestial or terrestrial hemisphere .
• 1804 Either of the two halves of the cerebrum. .