Hemisphere
Pronunciation : Hem"i*sphere
Part of Speech : n.
Etymology : [L. hemisphaerium, Gr. h?misph?re. See Hemi-, and Sphere.]
Definition : 1. A half sphere; one half of a sphere or globe, when divided by a plane passing through its center.
2. Half of the terrestrial globe, or a projection of the same in a map or picture.
3. The people who inhabit a hemisphere. He died . . . mourned by a hemisphere. J. P. Peters. ten Cerebral hemispheres. (Anat.) See Brain. -- Magdeburg hemispheres (Physics), two hemispherical cups forming, when placed together, a cavity from which the air can be withdrawn by an air pump; -- used to illustrate the pressure of the air. So called because invented by Otto von Guericke at Magdeburg.
Source : Webster's Unabridged Dictionary, 1913