Which position describes a patient lying face downward?

The term that describes a patient lying face downward is "prone." This position is commonly used in various medical procedures and examinations, particularly in radiography. When a patient is in the prone position, their back is facing up, allowing for specific imaging and treatment approaches that may be necessary for certain conditions or diagnostic processes.

In contrast, the supine position refers to a patient lying on their back, which is opposite of the prone position. The decubitus position refers to a patient lying on their side, and the oblique position involves the patient being tilted or angled in a way that is not upright or fully lateral. Each of these positions serves distinct purposes in medical imaging and patient care, highlighting the importance of accurately identifying patient orientation during procedures.