generated at
molt

verb no object
(of an animal) shed old feathers, hair, or skin, or an old shell, to make way for a new growth:
〈鳥が〉羽毛が生え替わる; 〈動物が〉毛などが生え替わる, 脱皮する
e.g. with object : the snake molts its skin
e.g. the adult birds were already molting into their winter shades of gray.
e.g. the last of his juvenile plumage had molted.

noun
a loss of plumage, skin, or hair, especially as a regular feature of an animal's life cycle:
抜け替わり, 脱皮, その時期
e.g. the mountain goat is brilliant white after the autumn molt
e.g. in the complete life cycle there are four molts.

ORIGIN
Middle English moute, from an Old English verb based on Latin mutare ‘to change’. For the intrusive -l-, compare with words such as fault.