Source : Webster's Revised Unabridged Dictionary (1913)

Desperate \Des"per*ate\, n.
   One desperate or hopeless. [Obs.]

Desperate \Des"per*ate\, a. [L. desperatus, p. p. of desperare.
   See {Despair}, and cf. {Desperado}.]
   1. Without hope; given to despair; hopeless. [Obs.]

            I am desperate of obtaining her.      --Shak.

   2. Beyond hope; causing despair; extremely perilous;
      irretrievable; past cure, or, at least, extremely
      dangerous; as, a desperate disease; desperate fortune.

   3. Proceeding from, or suggested by, despair; without regard
      to danger or safety; reckless; furious; as, a desperate
      effort. ``Desperate expedients.'' --Macaulay.

   4. Extreme, in a bad sense; outrageous; -- used to mark the
      extreme predominance of a bad quality.

            A desperate offendress against nature. --Shak.

            The most desperate of reprobates.     --Macaulay.

   Syn: Hopeless; despairing; desponding; rash; headlong;
        precipitate; irretrievable; irrecoverable; forlorn; mad;
        furious; frantic.

Source : WordNet®

desperate
     adj 1: arising from or marked by despair or loss of hope; "a
            despairing view of the world situation"; "the last
            despairing plea of the condemned criminal"; "a
            desperate cry for help"; "helpless and desperate--as
            if at the end of his tether"; "her desperate screams"
            [syn: {despairing}]
     2: desperately determined; "do-or-die revolutionaries"; "a
        do-or-die conflict" [syn: {do-or-die(a)}]
     3: (of persons) dangerously reckless or violent as from urgency
        or despair; "a desperate criminal"; "taken hostage of
        desperate men"
     4: showing extreme courage; especially of actions courageously
        undertaken in desperation as a last resort; "made a last
        desperate attempt to reach the climber"; "the desperate
        gallantry of our naval task forces marked the turning
        point in the Pacific war"- G.C.Marshall; "they took heroic
        measures to save his life" [syn: {heroic}]
     5: showing extreme urgency or intensity especially because of
        great need or desire; "felt a desperate urge to confess";
        "a desperate need for recognition"
     6: fraught with extreme danger; nearly hopeless; "a desperate
        illness"; "on all fronts the Allies were in a desperate
        situation due to lack of materiel"- G.C.Marshall; "a dire
        emergency" [syn: {dire}]

desperate
     n : a person who is frightened and in need of help; "they prey
         on the hopes of the desperate"