safe sex
noun [ U ] uk/ˌseɪf ˈseks/ us/ˌseɪf ˈseks/
（采取针对艾滋病及其他性病的预防措施的）安全性交，安全房事
the use of condoms or other methods of avoiding catching a disease, especially AIDS (= a serious disease that destroys the body's ability to fight infection), from sexual activity with someone else
The leaflets encourage people to practise safe sex. 这些宣传页鼓励人们采用安全性行为。