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.