Source : Webster's Revised Unabridged Dictionary (1913)

Intersert \In`ter*sert"\, v. t. [imp. & p. p. {Interserted}; p.
   pr. & vb. n. {Interserting}.] [L. intersertus, p. p. of
   interserere to intersert; inter between + serere to join,
   weave.]
   To put in between other things; to insert. [Obs.]
   --Brerewood.