say it: HEM-i-sfir
hemisphere is a noun meaning "half of the terrestrial globe". It carries 3 recorded senses.
half of the terrestrial globe
half of a sphere
either half of the cerebrum
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for hemisphere come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.