Source : Webster's Revised Unabridged Dictionary (1913)

Cold-blooded \Cold"-blood`ed\, a.
   1. Having cold blood; -- said of fish or animals whose blood
      is but little warmer than the water or air about them.

   2. Deficient in sensibility or feeling; hard-hearted.

   3. Not thoroughbred; -- said of animals, as horses, which are
      derived from the common stock of a country.

Source : WordNet®

cold-blooded
     adj 1: without compunction or human feeling; "in cold blood";
            "cold-blooded killing"; "insensate destruction" [syn:
            {cold}, {inhuman}, {insensate}]
     2: having cold blood (in animals whose body temperature is not
        internally regulated) [ant: {warm-blooded}]