What is the meaning of the prefix 'epi-'?

The prefix 'epi-' is derived from Greek, meaning "on" or "upon." It is commonly used in medical terminology to describe something that is situated on or above a structure or area. For instance, when referring to the epidermis, it denotes the outermost layer of skin, which lies on top of the dermis. This prefix is critical in understanding anatomical terms and their applications in coding and classification within a clinical setting.

The other choices suggest alternative meanings such as "under," "over," and "above," which do not accurately capture the specific implication of 'epi-' in this context. While "above" might seem relevant, it does not convey the precise concept of being directly "on" or "upon" another structure, making the chosen meaning the most accurate representation of the prefix.