What does recumbent mean?

Recumbent means lying back or lying down, or resting or leaning against something.
Back lying position, the client's head and shoulders are slightly elevated on a small pillow and is used to provide comfort and facilitate healing following certain surgeries or anaesthetics.
what is the purpose of dorsal examinaton position in physical examination?

to determine if a person isfaking a sciatic nerve problem
Dorsal Recumbency is lying on the back.

Dorsal = Back

Recumbent = lying down