painkiller

名词 painkiller:

1. a medicine used to relieve pain
   同义词：analgesic, anodyne, pain pill

pain.kill.er

n.（名词）
An agent, such as an analgesic drug, that relieves pain.
镇痛剂：一种药剂，如止痛药，减轻疼痛

【引伸】
pain.kill.ing
adj.（形容词）