Source : Webster's Revised Unabridged Dictionary (1913)

Interleave \In`ter*leave"\, v. t. [imp. & p. p. {Interleaved};
   p. pr. & vb. n. {Interleaving}.] [Pref. inter- + leaf.]
   To insert a leaf or leaves in; to bind with blank leaves
   inserted between the others; as, to interleave a book.