Source : Webster's Revised Unabridged Dictionary (1913)

Heighten \Height"en\ (h[imac]t"'n), v. t. [Written also
   {highten}.] [imp. & p. p. {Heightened}; p. pr. & vb. n.
   {Heightening}.]
   1. To make high; to raise higher; to elevate.

   2. To carry forward; to advance; to increase; to augment; to
      aggravate; to intensify; to render more conspicuous; --
      used of things, good or bad; as, to heighten beauty; to
      heighten a flavor or a tint. ``To heighten our
      confusion.'' --Addison.

            An aspect of mystery which was easily heightened to
            the miraculous.                       --Hawthorne.

Source : WordNet®

heighten
     v 1: become more extreme; "The tension heightened" [syn: {rise}]
     2: make more extreme; raise in quantity, degree, or intensity;
        "heightened interest"
     3: increase; "This will enhance your enjoyment"; "heighten the
        tension" [syn: {enhance}, {raise}]
     4: increase the height of; "The athletes kept jumping over the
        steadily heightened bars"
     5: make (one's senses) more acute; "This drug will sharpen your
        vision" [syn: {sharpen}]
     6: make more intense, stronger, or more marked; "The efforts
        were intensified", "Her rudeness intensified his dislike
        for her"; "Potsmokers claim it heightens their awareness";
        "This event only deepened my convictions" [syn: {intensify},
         {compound}, {deepen}]