What does molting mean?
Molting is the process by which an animal sheds and replaces an old outer covering, such as a snake’s skin, a crab’s shell, or a bird’s feathers. The newly formed covering may look soft, incomplete, or less protective, so animals often become less active and vulnerable while the change takes place. The word is especially associated with snakes and birds, but it can describe similar renewal in many other animals. In American English, "molting" is the usual spelling; British English commonly uses "moulting." Figuratively, the term can describe a person casting off an old identity, appearance, or way of life. It is a precise word for the deliberate biological replacement of an outer layer, rather than its more general loss or damage.
To shed and replace an old outer layer, especially skin or feathers.
"The caterpillar molted and left its old skin behind."
Used mainly of animals; the British spelling is "moulting."
In the process of shedding or replacing an old outer layer.
"A molting python lay motionless in its enclosure."
Common as an attributive modifier before a noun, such as "molting season."
A snake's dramatic skin-shedding is only the most visible form of moulting; birds, arthropods, and other animals also renew protective outer layers.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does molting come from?
Molting developed from Old English vocabulary associated with the casting off of skin or feathers. The underlying terminology has parallels in other Germanic languages, reflecting a widespread Germanic sense of shedding or sloughing. The modern word also survives in the British spelling variant "moulting," while American English generally uses "molting."
Related word forms
How molting is actually used
The spelling "molting" is standard in American English, while "moulting" is preferred in British English. The word is normally used of animals, but it can also describe a person metaphorically shedding an old identity or appearance.
Easily confused with molting
Molting means shedding an outer layer of skin or feathers, whereas moulding means shaping a material in a mould.