1. The idiopathic clinical changes (disease having no known cause) produced by focal damage to elastin fibers which results in looseness of he skin.

Elastin fibers refers to a protein which forms the principal substance of yellow elastic tissue fibers which is a type of connective tissue containing elastic fibers found in ligaments of the spinal column, in the cartilage of the external ear, and in the walls of some large blood vessels.

2. Etymology: from Greek anetos, "relaxed" + derma, "skin".