Which prefix means good?

• A. A-, AN-
• B. EU-
• C. PAN-
• D. -CELE

Answer: (C)

A useful idea in medical terminology is that prefixes modify the meaning of a word root. The prefix that means good is eu-, from Greek eu- meaning good or well. When attached to a root, it signals a favorable or normal condition, as in eupnea (normal breathing), euthanasia (mercy killing), or eugenics (study of good origins). The other options don’t convey “good”: A- or AN- are negating prefixes meaning without or lack, as in anemia or anhydrous; pan- means all or entire, indicating extent rather than quality; and -CELE is not a prefix used to denote goodness.