What is the correct meaning of "trans-" in medical terms?

In medical terminology, the prefix "trans-" signifies the concept of "across" or "through." This prefix is derived from Latin and is commonly used to denote a process that occurs across boundaries or in relation to movement from one area to another. For instance, in terms such as "transfusion," it refers to the transfer of blood from one individual to another, indicating that the blood moves across from a donor to a recipient. Similarly, in "transdermal," the term suggests a delivery method that occurs across the skin.

Understanding the meaning of "trans-" is essential for interpreting various medical terms, as it often defines the nature of an action or process, particularly in contexts such as pharmacology, anatomy, and procedures. The other options—under, over, and away from—do not convey this idea of movement across or through, which is crucial in many medical concepts.