Decubitus

Commonly used in medicine, the word decubitus is used to mean 'lying down'. It is derived from the Latin verb decumbere 'to lie down'.
When medical professionals use this term to describe the position of a patient, they first state the part of the body on which the patient is resting followed by the word decubitus. For example, the right lateral decubitus would mean that the patient is lying on his or her right side. Left lateral decubitus position (LLDP) would mean that the patient is lying on his or her left side.