to gradually take away someone else's rights, or to take control of someone's time, work, etc.

What the company is proposing encroaches on the rights of individuals. 公司打算做的这件事侵犯了个人的权利。

I resent it that my job is starting to encroach on my family life. 我的工作开始占据本来属于我家庭生活的时间，我很讨厌这一点。

to gradually cover more and more of an area of land

They have promised that the development will not encroach on public land. 他们已经承诺这个开发项目不会侵占公共土地。