Hypodermis

Part of speech: noun

Definitions

1. The deepest layer of skin lying beneath the epidermis, composed mainly of fat and connective tissue that insulates and cushions the body
2. The subcutaneous tissue layer located under the outer skin, containing fatty deposits and fibrous material that provides support and thermal protection
3. The inner skin layer below the epidermis that consists chiefly of adipose tissue and collagen, serving to anchor skin and regulate body temperature

Etymology: The layer of skin beneath the dermis has a name built from two Greek pieces that simply mean "under" and "skin." The prefix comes from Ancient Greek "hupo-", meaning "under" or "beneath," and it appears in many English words such as "hypothesis" and "hypnosis." The second part is the Greek "derma," "skin," which gives English "dermis" for the true skin layer, the one that sits above the tissue in question. The term is a straightforward compound: "hypo-" plus "dermis," so its literal sense is "the layer under the dermis." Nothing about the word is figurative. Anatomists formed it by joining the prefix to the existing name for the skin, a method that let them name newly described structures using classical building blocks.

Synonyms: subcutis, subcutaneous tissue, inner layer