1rare The action of stripping a person of his or her wealth or assets, especially by dishonest or unscrupulous means. Compare "fleece".
Frequently as part of an extended metaphor.
2literal The action or process of removing feathers, especially from the carcass of a poultry bird in preparation for cooking, typically by mechanical means. Also: an instance of this. Frequently attributive, as "defeathering machine", "defeathering tank", etc.
3The shedding of feathers by a bird; specifically loss of feathers on the brood patch on the belly during the breeding season.
Late 19th century; earliest use found in The Graphic: an illustrated weekly newspaper. From defeather + -ing.