Source : Webster's Revised Unabridged Dictionary (1913)

Intense \In*tense"\, a. [L. intensus stretched, tight, p. p. of
   intendere to stretch: cf. F. intense. See {Intend}, and cf.
   {Intent}, and cf. {Intent}, a.]
   1. Strained; tightly drawn; kept on the stretch; strict; very
      close or earnest; as, intense study or application;
      intense thought.

   2. Extreme in degree; excessive; immoderate; as:
      (a) Ardent; fervent; as, intense heat.
      (b) Keen; biting; as, intense cold.
      (c) Vehement; earnest; exceedingly strong; as, intense
          passion or hate.
      (d) Very severe; violent; as, intense pain or anguish.
      (e) Deep; strong; brilliant; as, intense color or light.

                In this intense seclusion of the forest.
                                                  --Hawthorne.

Source : WordNet®

intense
     adj 1: in an extreme degree; "intense heat"; "intense anxiety";
            "intense desire"; "intense emotion"; "the skunk's
            intense acrid odor"; "intense pain"; "enemy fire was
            intense" [ant: {mild}]
     2: extremely sharp or intense; "acute pain"; "felt acute
        annoyance"; "intense itching and burning" [syn: {acute}]
     3: (of color) having the highest saturation; "vivid green";
        "intense blue" [syn: {vivid}]