hemisphere

NOUN /hɛmɪ,sfir/
10 LETTERS · 3 SYLLABLES · STARTS WITH H

hemisphere is a valid 10-letter word worth 20 points in Scrabble and 20 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
H4E1M3I1S1P3H4E1R1E1
4 + 1 + 3 + 1 + 1 + 3 + 4 + 1 + 1 + 1 =20 PTS
DOUBLE WORD → 40TRIPLE WORD → 60
MEANING

What does hemisphere mean?