Source : Webster's Revised Unabridged Dictionary (1913)

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.