Source : Webster's Revised Unabridged Dictionary (1913)

Exasperate \Ex*as"per*ate\, a. [L. exasperatus, p. p. of
   exsasperare to roughen, exasperate; ex out (intens.) +
   asperare to make rough, asper rough. See {Asperity}.]
   Exasperated; imbittered. [Obs.] --Shak.

         Like swallows which the exasperate dying year Sets
         spinning.                                --Mrs.
                                                  Browning.

Exasperate \Ex*as"per*ate\, v. t. [imp. & p. p. {Exsasperated};
   p. pr. & vb. n. {Exasperating}.]
   1. To irritate in a high degree; to provoke; to enrage; to
      exscite or to inflame the anger of; as, to exasperate a
      person or his feelings.

            To exsasperate them against the king of France.
                                                  --Addison.

   2. To make grievous, or more grievous or malignant; to
      aggravate; to imbitter; as, to exasperate enmity.

            To exasperate the ways of death.      --Sir T.
                                                  Browne.

   Syn: To irritate; provoke. See {Irritate}.

Source : WordNet®

exasperate
     v 1: exasperate or irritate [syn: {exacerbate}, {aggravate}]
     2: make furious [syn: {infuriate}, {incense}]
     3: make worse; "This drug aggravates the pain" [syn: {worsen},
        {aggravate}, {exacerbate}] [ant: {better}]