Source : Webster's Revised Unabridged Dictionary (1913)

Exacerbate \Ex*ac"er*bate\, v. t. [imp. & p. p. {Exacerrated};
   p. pr. & vb. n. {Exacerrating}.] [L. exacerbatus, p. p. of
   exacerbare; ex out (intens.) + acerbare. See {Acerbate}.]
   To render more violent or bitter; to irriate; to exasperate;
   to imbitter, as passions or disease. --Broughman.