Source : Webster's Revised Unabridged Dictionary (1913)

Insertion \In*ser"tion\, n. [L. insertio: cf. F. insertion. See
   {Insert}.]
   1. The act of inserting; as, the insertion of scions in
      stocks; the insertion of words or passages in writings.

   2. The condition or mode of being inserted or attached; as,
      the insertion of stamens in a calyx.

   3. That which is set in or inserted, especially a narrow
      strip of embroidered lace, muslin, or cambric.

   4. (Anat.) The point or part by which a muscle or tendon is
      attached to the part to be moved; -- in contradistinction
      to its origin.

   {Epigynous insertion} (Bot.), the insertion of stamens upon
      the ovary.

   {Hypogynous insertion} (Bot.), insertion beneath the ovary.

Source : WordNet®

insertion
     n 1: a message (spoken or written) that is introduced or
          inserted; "with the help of his friend's interpolations
          his story was eventually told"; "with many insertions in
          the margins" [syn: {interpolation}]
     2: the act of putting one thing into another [syn: {introduction},
         {intromission}]