passive smoking
noun [ U ] uk/ˌpæs.ɪv ˈsməʊ.kɪŋ/ us/ˌpæs.ɪv ˈsmoʊ.kɪŋ/
被动吸烟，吸二手烟
the unwanted breathing in of other people's cigarette smoke, especially by people who do not smoke
Doctors say passive smoking has caused his lung cancer. 医生说被动吸烟导致他患上了肺癌。