What is the X in X-mas?
exfoliation ex·fo·li·a·tion (ěks-fō'lē-ā'shən)
Detachment and shedding of superficial cells of an epithelium or a tissue surface.
Scaling or desquamation of the horny layer of epidermis.
Loss of deciduous teeth following physiological loss of root structure.
Extrusion of permanent teeth as a result of disease or loss of opposing teeth.
separation of successive thin shells, or spalls, from massive rock such as granite or basalt; it is common in regions that have moderate rainfall. The thickness of individual sheet or plate may be from a few millimetres to a few metres.