What does prefix anti- mean? Provide an example term.

• A. Against; antioxidant
• B. Against; antibiotic
• C. For; anti-inflammatory
• D. Behind; antepartum

Answer: (B)

Anti- means against or opposed to. A classic example is antibiotic, which uses anti- plus biotic (life) to mean something that fights against bacteria. This showcases the prefix clearly: it signals opposition to living organisms, specifically the bacteria that antibiotics target.

Other terms show the prefix in different ways. An antioxidant also starts with anti-, but it refers to opposing oxidation in chemistry, not opposing a living organism. A term like anti-inflammatory is indeed about opposing inflammation, but in the given pairing the descriptor suggests “for” rather than “against,” which clashes with the meaning of anti-. Antepartum uses a different prefix, ante-, meaning before, not anti-. So antibiotic best demonstrates the meaning of anti- in medical terminology.