hemisphere

UK: /ˈhɛmɪsfɪə^r/ US: /ˈhɛmɪˌsfɪr/ ,(hem′i sfēr′)

WordReference Random House Learner's Dictionary of American English © 2025

hem•i•sphere /ˈhɛmɪˌsfɪr/   n. [countable]

1. Geography, Place Names half of the earth; one of the halves into which the earth may be divided:
   [often: Hemisphere] the Western Hemisphere; the Southern Hemisphere.
2. Mathematics a half of a sphere.

hem•i•spher•ic /ˌhɛmɪˈsfɛrɪk/  hem•i•spher•i•cal, adj. 

WordReference Random House Unabridged Dictionary of American English © 2025

hem•i•sphere  (hem′i sfēr′), n. 

1. Geography, Place Names (often cap.) half of the terrestrial globe or celestial sphere, esp. one of the halves into which the earth is divided. Cf. Eastern Hemisphere, Western Hemisphere, Northern Hemisphere, Southern Hemisphere.
2. Geography a map or projection representing one of these halves.
3. Mathematics a half of a sphere.
4. Anatomy either of the lateral halves of the cerebrum or cerebellum.
5. the area within which something occurs or dominates;
   sphere;
   realm.

• Latin
• Old French emispere
• Greek hēmisphaírion; replacing Middle English emysperie
• Latin hēmisphaerium
• 1325–75

Collins Concise English Dictionary © HarperCollins Publishers::

hemisphere / ˈhɛmɪˌsfɪə/ noun

1. one half of a sphere
2. half of the terrestrial globe, divided into northern and southern hemispheres by the equator or into eastern and western hemispheres by some meridians, usually 0° and 180°
3. a map or projection of one of the hemispheres
4. either of the two halves of the celestial sphere that lie north or south of the celestial equator
5. short for cerebral hemisphere

hemispheric / ˌhɛmɪˈsfɛrɪk/, ˌhemiˈspherical adjective