hemisphere

noun

1. 1

   Half of the celestial sphere, as divided by either the ecliptic or the celestial equator .

2. 2

   A realm or domain of activity .

3. 3

   Half of the Earth, such as the Northern Hemisphere, Southern Hemisphere, Western Hemisphere or Eastern Hemisphere, Land Hemisphere, Water Hemisphere etc. .

4. 4

   Any half-sphere, formed by a plane intersecting the center of a sphere. .

5. 5

   A map or projection of a celestial or terrestrial hemisphere .

6. 6

   Either of the two halves of the cerebrum. .