Which medical prefix means 'abnormal'?

The prefix that means 'abnormal' is "para-." In medical terminology, "para-" is often used to indicate a condition that is alongside, beyond, or abnormal in relation to something else. For instance, "parathyroid" refers to glands that are located beside the thyroid glands, which can suggest a function that is abnormal compared to the standard thyroid function.

The other prefixes provided have different meanings. "Ecto-" refers to something that is outside or external, "infer-" is related to being below or under, and "extra-" denotes something that is outside of or beyond normal limits. Understanding these prefixes is essential in medical terminology as they help accurately describe various conditions, locations, or characteristics related to medical terms.