1. (a.) Having cold blood; -- said of fish or animals whose blood is but little warmer than the water or air about them.

2. (a.) Deficient in sensibility or feeling; hard-hearted.

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

apathetic barbaric barbarous brutal callous cool cruel dispassionate heartless imperturbable indifferent inhuman insensitive merciless pitiless poikilothermic ruthless savage steely stony thick-skinned uncaring unemotional unexcited unfeeling unimpassioned unmoved unresponsive unsympathetic vicious