To throw off scales or flakes; peel off in thin fragments; desquamate: as, the exfoliating bark of a tree.Specifically In surgery, to separate and come off in scales, as carious bone.In mineralogy, to split into scales; especially, to become scaly at the surface in consequence of heat or decomposition: as, vermiculite exfoliates before the blowpipe.To scale; free from scales or splinters.