Hem″i‐sphere (?), n. [L. hemisphaerium, Gr. �; � half = � sphere: cf. F. hémisphère. See Hemi-, and Sphere.] 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.
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hemispheres(Physics), two hemispherical cups forming, when placed together, a cavity from which the air can be withdrawn by an air pump; — used to illustrate the pressure of the air.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.