Due to severe infection, the doctors had to amputate his right arm.

amputate 是动词，来自拉丁语 amputare（切除）。这个词由前缀 am-（表示"周围"或"完全"）和 putare（修剪、清理）组成，字面意思是"彻底修剪"。在医学上特指"截肢"，即通过手术切除肢体或身体部位。