Hemisphere
来自Big Physics
late 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’.
wiktionary
From Latin hemisphaerium, from Ancient Greek ἡμισφαίριον(hēmisphaírion), from ἡμι-(hēmi-, “half”) + σφαῖρα(sphaîra, “sphere”); hemi- + sphere
etymonline
hemisphere (n.)
late 14c., hemysperie, in reference to the celestial sphere, from Late Latin hemisphaerium, from Greek hēmisphairion, from hēmi- "half" (see hemi-) + sphaira "sphere" (see sphere). Spelling reformed 16c. Of the Earth, from 1550s; of the brain, 1804.
