Source : Webster's Revised Unabridged Dictionary (1913)

Acrid \Ac"rid\, a. [L. acer sharp; prob. assimilated in form to
   acid. See {Eager}.]
   1. Sharp and harsh, or bitter and not, to the taste; pungent;
      as, acrid salts.

   2. Causing heat and irritation; corrosive; as, acrid
      secretions.

   3. Caustic; bitter; bitterly irritating; as, acrid temper,
      mind, writing.

   {Acrid poison}, a poison which irritates, corrodes, or burns
      the parts to which it is applied.

Source : WordNet®

acrid
     adj 1: strong and sharp; "the acrid smell of burning rubber"
     2: harsh or corrosive in tone; "an acerbic tone piercing
        otherwise flowery prose"; "a barrage of acid comments";
        "her acrid remarks make her many enemies"; "bitter words";
        "blistering criticism"; "caustic jokes about political
        assassination, talk-show hosts and medical ethics"; "a
        sulfurous denunciation" [syn: {acerb}, {acerbic}, {acid},
        {bitter}, {blistering}, {caustic}, {sulfurous}, {sulphurous},
         {venomous}, {virulent}, {vitriolic}]