Definitions
1.nounHalf of the celestial sphere, as divided by either the ecliptic or the celestial equator .
2.nounA realm or domain of activity .
3.nounHalf of the Earth, such as the Northern Hemisphere, Southern Hemisphere, Western Hemisphere or Eastern Hemisphere, Land Hemisphere, Water Hemisphere etc. .
4.nounAny half-sphere, formed by a plane intersecting the center of a sphere. .
5.nounA map or projection of a celestial or terrestrial hemisphere .
6.nounEither of the two halves of the cerebrum. .