Exfoliate \Ex*fo"li*ate\, v. i. [imp. & p. p. {Exfoliated}; p. pr. & vb. n. {Exfoliating}.] [L. exfoliare to strip of leaves; ex out, from + folium leaf.] 1. To separate and come off in scales or lamin[ae], as pieces of carious bone or of bark. 2. (Min.) To split into scales, especially to become converted into scales at the result of heat or decomposition.