N-VAR
侵占;侵蚀;蚕食
You can describe the action or process of encroaching on something as encroachment .
例句
It's a sign of the encroachment of commercialism in medicine...
这是医药界被逐渐商业化的一个的征兆。
The problem was to safeguard sites from encroachment by property development.
问题是要保护遗址免受房地产开发商的侵占。