The prefix hemi- means which?

• A. Half
• B. Water
• C. Different
• D. Liver

Answer: (A)

Hemi- denotes half. This prefix comes from Greek and is used in medical terms to indicate that something is one half of a whole—for example, a hemisphere is one half of the globe, hemiparesis is weakness on one half of the body, and hemianopia is loss of vision in half of the visual field. That’s why the correct interpretation is that hemi- means half.

The other options don’t fit this prefix because they refer to different roots: water is hydro- or hydr-, different is hetero- (or allo-), and liver is hepato- (or hepatic-).