MOULT, a term for the shedding of feathers at the periodic renewal of the plumage by birds, and so transferred to the periodic shedding of the old skin, shell, etc., by other animals. The word is seen in O. Eng. in the verb bimutian, to exchange; from Lat. mutare, to change; cf. mod. Ger. mausen, mausern; the earlier forms in English are mout, mute; the insertion of the /, as in " fault," dates from the 16th century.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)