merciless

adj.

残忍的；无怜悯之心的；蛇蝎心肠；无情

1. His refusal was a merciless blow to us.
   他的拒绝对我们是一个无情的打击。
2. It was typical of him to be so merciless.
   只有他才会这么冷酷无情。
3. The killer was merciless.
   凶手残酷无情。

Ignoring a merciless act
"Conduct merciless mass terror": decossackization on the Don, 1919
Facing a merciless enemy: HIV / AIDS and the South African armed forces.
From Merciless Retirement to Friendly Settlement:Humane Concern for Ex-Service Athletes
"A Merciless Source of Happy Memories": Gaston Roupnel and the Folklore of Burgundian Terroir
Vascular endothelium: a vulnerable transit zone for merciless sodium
"Merciless Indian Savages"and the Declaration of Independence: Native Americans Translate the Ecunnaunuxulgee Document
[Truth disclosure in physicians' dialogue: compassionate lie or merciless statistics?]
The leaf beetle Diabrotica virgifera virgifera LeConte: a merciless entomological challenge for agriculture.
Modeling the Realities of Research Experience: Collaboration Against Common and Merciless Foes