molt

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To shed part or all of a coat or an outer covering, such as feathers, cuticle, or skin, which is then replaced by a new growth.
• intransitive verb To shed or cast off (a bodily covering).
• noun The act or process of molting.
• noun The material cast off during molting.

from The Century Dictionary.

• An obsolete preterit of melt.
• To shed or cast, as feathers, hair, or skin; slough off: often used figuratively.
• To cast or shed feathers, hair, skin, or the like; undergo or accomplish a molt; exuviate; mew. See the noun.
• To be about to be cast off or shed, as plumage.
• noun The act or process of shedding or casting any tegumentary, cuticular, or exoskeletal structures or appendages, as feathers, hair, skin, nails, horns, hoofs, claws, or shell; ecdysis; exuviation.
• noun The period or time of molting.

from the GNU version of the Collaborative International Dictionary of English.

• imp. of melt.
• transitive verb To cast, as the hair, skin, feathers, or the like; to shed.
• intransitive verb To shed or cast the hair, feathers, skin, horns, or the like, as an animal or a bird.
• noun The act or process of changing the feathers, hair, skin, etc.; molting.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb intransitive To shed hair, feathers, skin, horns etc. and replace it by a fresh layer.
• verb transitive To shed in such a manner.
• noun The skin or feathers cast off during the process of molting.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb cast off hair, skin, horn, or feathers
• noun periodic shedding of the cuticle in arthropods or the outer skin in reptiles