Source : Webster's Revised Unabridged Dictionary (1913)

Derogatory \De*rog"a*to*ry\, a.
   Tending to derogate, or lessen in value; expressing
   derogation; detracting; injurious; -- with from to, or unto.

         Acts of Parliament derogatory from the power of
         subsequent Parliaments bind not.         --Blackstone.

         His language was severely censured by some of his
         brother peers as derogatory to their other. --Macaulay.

   {Derogatory clause in a testament} (Law), a sentence of
      secret character inserted by the testator alone, of which
      he reserves the knowledge to himself, with a condition
      that no will he may make thereafter shall be valid, unless
      this clause is inserted word for word; -- a precaution to
      guard against later wills extorted by violence, or
      obtained by suggestion.