exfoliar

Exfoliar is an adjective used primarily in botany and horticulture to describe surfaces or tissues that shed or peel away in layers. In this context, exfoliation refers to the natural process of shedding outer layers, such as bark or epidermal tissue. Exfoliar bark is a characteristic of some trees that peel in sheets or ribbons to reveal new growth or for protective reasons. The term is commonly applied to describe trees with visibly peeling bark, including several eucalyptus species and other taxa known for their textured or multicolored trunks.

In skincare and medicine, exfoliation refers to the removal of dead skin cells from the surface of the skin to improve texture and appearance. The standard terms are exfoliate (the verb) and exfoliation (the noun), while exfoliar is not commonly used in English. Exfoliating agents can be mechanical, such as scrubs or brushes, or chemical, such as alpha-hydroxy acids or beta-hydroxy acids, and products labeled as exfoliants are designed to promote cell turnover. Overuse or aggressive exfoliation can lead to skin irritation or barrier damage, so guidelines typically recommend moderate frequency and patch testing.

Etymology-wise, exfoliar derives from Latin exfoliatus, the past participle of ex foli- “to peel off,” from ex- “out” and folium “leaf.” The word is distinct from foliar, which relates to leaves, and from exfoliation as a general process. In practice, exfoliar is rare in English, with exfoliate, exfoliation, and exfoliating being the standard forms.