hemisphere

/ˌhɛməˈsfɪər/

/ˈhɛmɪsfɪə/

Other forms: hemispheres

A hemisphere is half of a sphere. If it’s a cold winter in the northern hemisphere, take a winter getaway to sunbathe somewhere in the southern hemisphere.

Hemisphere comes from the Greek, and combines the prefix hemi-, for "half," with sphere, or "perfectly round ball." We talk about the earth as divided at the equator into the northern and southern hemispheres (or divided at the prime meridian into eastern and western hemispheres). In biology, there are two cerebral, or brain, hemispheres — also known as the right and left sides of the brain.

Definitions of hemisphere

1. noun

   half of a sphere
   type of:

   subfigure

   a figure that is a part of another figure
2. noun

   half of the terrestrial globe
   examples:

   northern hemisphere

   the hemisphere that is to the north of the equator

   southern hemisphere

   the hemisphere to the south of the equator

   types:

   eastern hemisphere, orient

   the hemisphere that includes Eurasia and Africa and Australia

   New World, occident, western hemisphere

   the hemisphere that includes North America and South America

   type of:

   geographic area, geographic region, geographical area, geographical region

   a demarcated area of the Earth
3. noun

   either half of the cerebrum
   synonyms: cerebral hemisphere

   types:

   left brain, left hemisphere

   the cerebral hemisphere to the left of the corpus callosum that controls the right half of the body

   right brain, right hemisphere

   the cerebral hemisphere to the right of the corpus callosum that controls the left half of the body

   type of:

   neural structure

   a structure that is part of the nervous system