▪ a half of the earth, usually as divided into northern and southern halves by the equator, or into western and eastern halves by an imaginary line passing through the poles.
▪ a half of the celestial sphere.
▪ each of the two parts of the cerebrum (left and right) in the brain of a vertebrate:"the left hemisphere plays a dominant role in the comprehension of language"
Word Originlate Middle English (in the sense ‘half the celestial sphere, the sky’): from Old French emisphere, via Latin from Greek hēmisphairion, from hēmi- ‘half’ + sphaira ‘sphere’.
