n.

1. 传染；侵染[U]
   Are you sure there is no danger of infection now?

   你敢不敢肯定现在已经没有传染的危险了？

2. 传染病[C]
3. 影响；感染[U]
   He suffered from a lung infection.

   他肺部受到了感染。

n.

1. the process of infecting or the state of being infected.
2. an infectious disease.