Hem"i*sphere (?), n. [L. hemisphaerium, Gr. ; half = sphere: cf. F. h'emisphere. See Hemi-, and Sphere.]
A half sphere; one half of a sphere or globe, when divided by a plane passing through its center.
Half of the terrestrial globe, or a projection of the same in a map or picture.
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Magdeburg hemispheres Physics, two hemispherical cups forming, when placed together, a cavity from which the air can be withdrawn by an air pump; -- used to illustrate the pressure of the air.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.
© Webster 1913.