decubitus (n.)

"posture and manner assumed by sick persons lying in bed," 1866, Modern Latin, from past participle of Latin decumbere "to lie down," from de "down" (see de-) + -cumbere "take a reclining position," related to cubare "lie down" (see cubicle). Sometimes also "a bed-sore." Related: Decubital, decubitation (1660s as "action of lying down").