cold-blooded
adj
1 (biology 生) having a blood temperature which varies with the temperature of the surroundings 冷血的(血液温度随环境温度的高低而改变的)
Reptiles are cold-blooded. 爬行动物是冷血的.
2 (derog 贬) (of people or actions) without pity; cruel (指人或行动)无情的, 残酷的
a cold-blooded murderer, murder 残忍的谋杀者、 谋杀.
The hardened professional smuggler, on the other hand, is never troubled by such feelings, even if he has five hundred gold watches hidden in his suitcase.