Ekdysis

Part of speech: noun

Definitions

1. The process of shedding old skin or exoskeleton, particularly in reptiles and arthropods
2. A biological mechanism by which organisms replace old outer coverings to accommodate growth
3. The act that occurs in certain species as they mature and need to remove their previous protective layers

Etymology: Ekdysis comes from the Greek "ekdysis," meaning "a getting out" or "a stripping off," built from "ek," "out of," and "dyein," "to put on" or "to sink." The Greek verb "ekdyein" meant to take off a garment or to strip away, and the ancient Greeks applied it to snakes shedding their skin and to other creatures casting off their outer coverings. The term passed into scientific use as a way of describing this periodic moulting, which lets an animal outgrow a rigid shell, cuticle or skin that cannot expand with its body. Because the word has a clear Greek structure, English speakers can see its parts at work. Its relative "ecdysis" is the spelling more common in some modern texts, and both forms point back to the same idea of getting out of an old covering. The word stayed closely tied to zoology, where it describes the moult of insects, crustaceans and reptiles.