The sub-cutaneous layer is an important part of the skin. (The skin is also known as the "integument", or "integumentary system").
“Sub-cutaneous” (or “subcutaneous”) is also an adjective used to mean “beneath the skin”. An example of "sub-cutaneous" used as an adjective is the expression "sub-cutaneous injection" which refers to an injection into the sub-cutaneous layer of the skin.
To view the location of the sub-cutaneous layer relative to other parts of the skin see the diagram of the structure of the skin. This may be of particular interest to students of courses in massage, reflexology, beauty therapies, and other health science or clinical courses.