WordWeb Online

1. Strong and sharp
   "the acrid smell of burning rubber";
   - pungent
    
2. Harsh or corrosive in tone
   "her acrid remarks make her many enemies";
   - acerb, acerbic, acid, bitter, blistering, caustic, sulfurous [N. Amer], sulphurous [Brit, Cdn], virulent, vitriolic, acidulous, sulphureous [Brit]

See also: tasty, unpleasant