(encroaches, encroaching, encroached)
1.
If one thing encroaches on another, the first thing spreads or becomes stronger, and slowly begins to restrict the power, range, or effectiveness of the second thing. (FORMAL)
The new institutions do not encroach on political power...
The movie industry had chosen to ignore the encroaching competition of television.
VERB: V on/upon n, V-ing [disapproval]
2.
If something encroaches on a place, it spreads and takes over more and more of that place. (FORMAL)
The rhododendrons encroached ever more on the twisting drive...
I turned into the dirt road and followed it through encroaching trees and bushes.
VERB: V on n, V-ing