People trapped in confined spaces may become asphyxiated due to lack of oxygen.

asphyxiated 是动词 asphyxiate 的过去分词形式。asphyxiate 由前缀 a-（表示"缺乏"）和希腊词根 sphyzein（"脉搏"）组成，字面意思是"脉搏停止"，引申为"窒息"。asphyxiated 表示"因缺氧而窒息的"状态。