The Collaborative International Dictionary of English v.0.48:

Insist \In*sist"\, v. i. [imp. & p. p. Insisted; p. pr. & vb.
   n. Insisting.] [F. insister, L. insistere to set foot upon,
   follow, persist; pref. in- in + sistere to stand, cause to
   stand. See Stand.]
   [1913 Webster]
   1. To stand or rest; to find support; -- with in, on, or
      upon. [R.] --Ray.
      [1913 Webster]

   2. To take a stand and refuse to give way; to hold to
      something firmly or determinedly; to be persistent,
      urgent, or pressing; to persist in demanding; -- followed
      by on, upon, or that; as, he insisted on these conditions;
      he insisted on going at once; he insists that he must have
      money.
      [1913 Webster]

            Insisting on the old prerogative.     --Shak.
      [1913 Webster]

            Without further insisting on the different tempers
            of Juvenal and Horace.                --Dryden.

   Syn: Insist, Persist.

   Usage: Insist implies some alleged right, as authority or
          claim. Persist may be from obstinacy alone, and either
          with or against rights. We insist as against others;
          we persist in what exclusively relates to ourselves;
          as, he persisted in that course; he insisted on his
          friend's adopting it. --C. J. Smith.
          [1913 Webster]

WordNet (r) 3.0 (2006):

insisting
    n 1: continual and persistent demands [syn: insistence,
         insisting]